diff --git a/src/@types/type-helpers.ts b/src/@types/type-helpers.ts
index f06f16ef86e..89c427059c3 100644
--- a/src/@types/type-helpers.ts
+++ b/src/@types/type-helpers.ts
@@ -75,3 +75,12 @@ export type NonFunctionPropertiesRecursive<Class> = {
 };
 
 export type AbstractConstructor<T> = abstract new (...args: any[]) => T;
+
+/**
+ * Type helper to mark all properties in `T` optional, while still mandating that at least 1
+ * of its properties be present.
+ *
+ * Distinct from {@linkcode Partial} as this requires at least 1 property to _not_ be undefined.
+ * @typeParam T - The type to render partial.
+ */
+export type AtLeastOne<T> = Partial<T> & EnumValues<{ [K in keyof T]: Pick<T, K> }>;
diff --git a/test/@types/vitest.d.ts b/test/@types/vitest.d.ts
index d4aa5a447f4..3113b02ffb0 100644
--- a/test/@types/vitest.d.ts
+++ b/test/@types/vitest.d.ts
@@ -11,6 +11,7 @@ import type { ToHaveEffectiveStatMatcherOptions } from "#test/test-utils/matcher
 import { expectedStatusType } from "#test/test-utils/matchers/to-have-status-effect-matcher";
 import type { toHaveTypesOptions } from "#test/test-utils/matchers/to-have-types";
 import { TurnMove } from "#types/turn-move";
+import { AtLeastOne } from "#types/type-helpers";
 import type { expect } from "vitest";
 
 declare module "vitest" {
@@ -42,7 +43,7 @@ declare module "vitest" {
      * Default `0` (last used move)
      * @see {@linkcode Pokemon.getLastXMoves}
      */
-    toHaveUsedMove(expected: MoveId | Partial<TurnMove>, index?: number): void;
+    toHaveUsedMove(expected: MoveId | AtLeastOne<TurnMove>, index?: number): void;
 
     /**
      * Matcher to check if a {@linkcode Pokemon Pokemon's} effective stat is as expected
diff --git a/test/test-utils/matchers/to-equal-array-unsorted.ts b/test/test-utils/matchers/to-equal-array-unsorted.ts
index c3388765841..e9e3c6c3855 100644
--- a/test/test-utils/matchers/to-equal-array-unsorted.ts
+++ b/test/test-utils/matchers/to-equal-array-unsorted.ts
@@ -6,7 +6,11 @@ import type { MatcherState, SyncExpectationResult } from "@vitest/expect";
  * @param expected - The array to check equality with
  * @returns Whether the matcher passed
  */
-export function toEqualArrayUnsorted(this: MatcherState, received: unknown, expected: unknown): SyncExpectationResult {
+export function toEqualArrayUnsorted(
+  this: MatcherState,
+  received: unknown,
+  expected: unknown[],
+): SyncExpectationResult {
   if (!Array.isArray(received)) {
     return {
       pass: false,
@@ -14,22 +18,16 @@ export function toEqualArrayUnsorted(this: MatcherState, received: unknown, expe
     };
   }
 
-  if (!Array.isArray(expected)) {
-    return {
-      pass: false,
-      message: () => `Expected to receive an array, but got ${this.utils.stringify(expected)}!`,
-    };
-  }
-
   if (received.length !== expected.length) {
     return {
       pass: false,
-      message: () => `Expected to receive array of length ${received.length}, but got ${expected.length}!`,
+      message: () => `Expected to receive array of length ${received.length}, but got ${expected.length} instead!`,
       actual: received,
       expected,
     };
   }
 
+  // Create shallow copies of the arrays in case we have
   const gotSorted = received.slice().sort();
   const wantSorted = expected.slice().sort();
   const pass = this.equals(gotSorted, wantSorted, [...this.customTesters, this.utils.iterableEquality]);
@@ -37,8 +35,10 @@ export function toEqualArrayUnsorted(this: MatcherState, received: unknown, expe
   return {
     pass,
     message: () =>
-      `Expected ${this.utils.stringify(received)} to exactly equal ${this.utils.stringify(expected)} without order!`,
-    actual: gotSorted,
+      pass
+        ? `Expected ${this.utils.stringify(received)} to NOT exactly equal ${this.utils.stringify(expected)} without order!`
+        : `Expected ${this.utils.stringify(received)} to exactly equal ${this.utils.stringify(expected)} without order!`,
     expected: wantSorted,
+    actual: gotSorted,
   };
 }
diff --git a/test/test-utils/matchers/to-have-ability-applied.ts b/test/test-utils/matchers/to-have-ability-applied.ts
index 1170850d844..f1846dca398 100644
--- a/test/test-utils/matchers/to-have-ability-applied.ts
+++ b/test/test-utils/matchers/to-have-ability-applied.ts
@@ -4,6 +4,7 @@ import type { Pokemon } from "#field/pokemon";
 
 import { getPokemonNameWithAffix } from "#app/messages";
 import { AbilityId } from "#enums/ability-id";
+import { getEnumStr } from "#test/test-utils/string-utils";
 import { isPokemonInstance, receivedStr } from "#test/test-utils/test-utils";
 import type { MatcherState, SyncExpectationResult } from "@vitest/expect";
 
@@ -28,14 +29,14 @@ export function toHaveAbilityAppliedMatcher(
   const pass = received.waveData.abilitiesApplied.has(expectedAbilityId);
 
   const pkmName = getPokemonNameWithAffix(received);
-  const expectedAbilityStr = `${AbilityId[expectedAbilityId]} (=${expectedAbilityId})`;
+  const expectedAbilityStr = getEnumStr(AbilityId, expectedAbilityId);
 
   return {
     pass,
     message: () =>
       pass
         ? `Expected ${pkmName} to NOT have applied ${expectedAbilityStr}, but it did!`
-        : `Expected ${pkmName} to have applied ${expectedAbilityStr}, but it did not!`,
+        : `Expected ${pkmName} to have applied ${expectedAbilityStr}, but it didn't!`,
     expected: expectedAbilityId,
     actual: received.waveData.abilitiesApplied,
   };
diff --git a/test/test-utils/matchers/to-have-battler-tag.ts b/test/test-utils/matchers/to-have-battler-tag.ts
index 51d020e8252..e2bee37849e 100644
--- a/test/test-utils/matchers/to-have-battler-tag.ts
+++ b/test/test-utils/matchers/to-have-battler-tag.ts
@@ -36,7 +36,7 @@ export function toHaveBattlerTag(
     message: () =>
       pass
         ? `Expected ${pkmName} to NOT have BattlerTagType.${expectedTagStr}, but it did!`
-        : `Expected ${pkmName} to have BattlerTagType.${expectedTagStr}, but it did not!`,
+        : `Expected ${pkmName} to have BattlerTagType.${expectedTagStr}, but it didn't!`,
     expected: expectedBattlerTagType,
     actual: received.summonData.tags.map(t => t.tagType),
   };
diff --git a/test/test-utils/matchers/to-have-fainted.ts b/test/test-utils/matchers/to-have-fainted.ts
index 33f8d439d19..f8d2f2d8917 100644
--- a/test/test-utils/matchers/to-have-fainted.ts
+++ b/test/test-utils/matchers/to-have-fainted.ts
@@ -15,17 +15,17 @@ export function toHaveFaintedMatcher(this: MatcherState, received: unknown): Syn
     };
   }
 
-  const { hp } = received;
-  const maxHp = received.getMaxHp();
   const pass = received.isFainted();
 
+  const hp = received.hp;
+  const maxHp = received.getMaxHp();
   const pkmName = getPokemonNameWithAffix(received);
 
   return {
     pass,
     message: () =>
       pass
-        ? `Expected ${pkmName} NOT to have fainted, but it did! (${hp}/${maxHp} HP)`
-        : `Expected ${pkmName} to have fainted, but it did not. (${hp}/${maxHp} HP)`,
+        ? `Expected ${pkmName} to NOT have fainted, but it did!`
+        : `Expected ${pkmName} to have fainted, but it didn't! (${hp}/${maxHp} HP)`,
   };
 }
diff --git a/test/test-utils/matchers/to-have-full-hp.ts b/test/test-utils/matchers/to-have-full-hp.ts
index e8ed8b78364..96285ab6340 100644
--- a/test/test-utils/matchers/to-have-full-hp.ts
+++ b/test/test-utils/matchers/to-have-full-hp.ts
@@ -15,16 +15,17 @@ export function toHaveFullHpMatcher(this: MatcherState, received: unknown): Sync
     };
   }
 
-  const pass = received.isFullHp() === true;
+  const pass = received.isFullHp();
 
-  const ofHpStr = `${received.getInverseHp()}/${received.getMaxHp()} HP`;
+  const hp = received.hp;
+  const maxHp = received.getMaxHp();
   const pkmName = getPokemonNameWithAffix(received);
 
   return {
     pass,
     message: () =>
       pass
-        ? `Expected ${pkmName} to NOT have full hp (${ofHpStr}), but it did!`
-        : `Expected ${pkmName} to have full hp, but found ${ofHpStr}.`,
+        ? `Expected ${pkmName} to NOT have full hp, but it did!`
+        : `Expected ${pkmName} to have full hp, but it didn't! (${hp}/${maxHp} HP)`,
   };
 }
diff --git a/test/test-utils/matchers/to-have-hp.ts b/test/test-utils/matchers/to-have-hp.ts
index 36bf6b90a68..d8ef90e91d2 100644
--- a/test/test-utils/matchers/to-have-hp.ts
+++ b/test/test-utils/matchers/to-have-hp.ts
@@ -1,4 +1,6 @@
 import { getPokemonNameWithAffix } from "#app/messages";
+// biome-ignore lint/correctness/noUnusedImports: TSDoc
+import type { Pokemon } from "#field/pokemon";
 import { isPokemonInstance, receivedStr } from "#test/test-utils/test-utils";
 import type { MatcherState, SyncExpectationResult } from "@vitest/expect";
 
@@ -20,13 +22,14 @@ export function toHaveHpMatcher(this: MatcherState, received: unknown, expectedH
   const pass = actualHp === expectedHp;
 
   const pkmName = getPokemonNameWithAffix(received);
-  const maxHp = received.getMaxHp();
 
   return {
     pass,
     message: () =>
       pass
-        ? `Expected ${pkmName} to NOT have ${expectedHp}/${maxHp} HP, but it did!`
-        : `Expected ${pkmName} to have ${expectedHp}/${maxHp} HP, but found ${actualHp}/${maxHp} HP.`,
+        ? `Expected ${pkmName} to NOT have ${expectedHp} HP, but it did!`
+        : `Expected ${pkmName} to have ${expectedHp} HP, but got ${actualHp} HP instead!`,
+    expected: expectedHp,
+    actual: actualHp,
   };
 }
diff --git a/test/test-utils/matchers/to-have-stat-stage-matcher.ts b/test/test-utils/matchers/to-have-stat-stage-matcher.ts
index 466f933d246..08799b62a98 100644
--- a/test/test-utils/matchers/to-have-stat-stage-matcher.ts
+++ b/test/test-utils/matchers/to-have-stat-stage-matcher.ts
@@ -1,5 +1,6 @@
 import { getPokemonNameWithAffix } from "#app/messages";
-import { type BattleStat, Stat } from "#enums/stat";
+import type { BattleStat } from "#enums/stat";
+import { getStatName } from "#test/test-utils/string-utils";
 import { isPokemonInstance, receivedStr } from "#test/test-utils/test-utils";
 import type { MatcherState, SyncExpectationResult } from "@vitest/expect";
 
@@ -34,7 +35,7 @@ export function toHaveStatStageMatcher(
   const pass = actualStage === expectedStage;
 
   const pkmName = getPokemonNameWithAffix(received);
-  const statName = Stat[stat];
+  const statName = getStatName(stat);
 
   return {
     pass,
diff --git a/test/test-utils/matchers/to-have-status-effect-matcher.ts b/test/test-utils/matchers/to-have-status-effect-matcher.ts
index bf1ecdd458b..b60d2639e46 100644
--- a/test/test-utils/matchers/to-have-status-effect-matcher.ts
+++ b/test/test-utils/matchers/to-have-status-effect-matcher.ts
@@ -46,7 +46,7 @@ export function toHaveStatusEffectMatcher(
       pass,
       message: () =>
         pass
-          ? `Expected ${pkmName} NOT to have ${expectedStr}, but it did!`
+          ? `Expected ${pkmName} to NOT have ${expectedStr}, but it did!`
           : `Expected ${pkmName} to have status effect ${expectedStr}, but got ${actualStr} instead!`,
       expected: expectedStatus,
       actual: actualEffect,
@@ -65,7 +65,7 @@ export function toHaveStatusEffectMatcher(
     pass,
     message: () =>
       pass
-        ? `Expected ${pkmName}'s status NOT to match ${this.utils.stringify(expectedStatus)}, but it did!`
+        ? `Expected ${pkmName}'s status to NOT match ${this.utils.stringify(expectedStatus)}, but it did!`
         : `Expected ${pkmName}'s status to match ${this.utils.stringify(expectedStatus)}, but got ${this.utils.stringify(actualStatus)} instead!`,
     expected: expectedStatus,
     actual: actualStatus,
diff --git a/test/test-utils/matchers/to-have-terrain-matcher.ts b/test/test-utils/matchers/to-have-terrain-matcher.ts
index 67292ef8bd9..c9ce4a21620 100644
--- a/test/test-utils/matchers/to-have-terrain-matcher.ts
+++ b/test/test-utils/matchers/to-have-terrain-matcher.ts
@@ -38,7 +38,7 @@ export function toHaveTerrainMatcher(
     message: () =>
       pass
         ? `Expected Arena to NOT have ${expectedStr} active, but it did!`
-        : `Expected Arena to have ${expectedStr} active, but got ${actualStr}!`,
+        : `Expected Arena to have ${expectedStr} active, but got ${actualStr} instead!`,
     actual,
     expected: expectedTerrainType,
   };
diff --git a/test/test-utils/matchers/to-have-types.ts b/test/test-utils/matchers/to-have-types.ts
index 59f43d9fd76..ff865a1cf73 100644
--- a/test/test-utils/matchers/to-have-types.ts
+++ b/test/test-utils/matchers/to-have-types.ts
@@ -39,17 +39,22 @@ export function toHaveTypes(
   const actualTypes = received.getTypes(...(options.args ?? [])).sort();
   const expectedTypes = expected.slice().sort();
 
-  const actualStr = stringifyEnumArray(PokemonType, actualTypes);
-  const expectedStr = stringifyEnumArray(PokemonType, expectedTypes);
   // Exact matches do not care about subset equality
   const matchers = options.exact
     ? [...this.customTesters, this.utils.iterableEquality]
     : [...this.customTesters, this.utils.subsetEquality, this.utils.iterableEquality];
-  const pass = this.equals(actualStr, expectedStr, matchers);
+  const pass = this.equals(actualTypes, expectedTypes, matchers);
+
+  const actualStr = stringifyEnumArray(PokemonType, actualTypes);
+  const expectedStr = stringifyEnumArray(PokemonType, expectedTypes);
+  const pkmName = getPokemonNameWithAffix(received);
 
   return {
     pass,
-    message: () => `Expected ${getPokemonNameWithAffix(received)} to have types ${expectedStr}, but got ${actualStr}!`,
+    message: () =>
+      pass
+        ? `Expected ${pkmName} to NOT have types ${expectedStr}, but it did!`
+        : `Expected ${pkmName} to have types ${expectedStr}, but got ${actualStr} instead!`,
     actual: actualTypes,
     expected: expectedTypes,
   };
diff --git a/test/test-utils/matchers/to-have-used-move-matcher.ts b/test/test-utils/matchers/to-have-used-move-matcher.ts
index ff1e0d95ce4..9f1e55fae5b 100644
--- a/test/test-utils/matchers/to-have-used-move-matcher.ts
+++ b/test/test-utils/matchers/to-have-used-move-matcher.ts
@@ -5,12 +5,14 @@ import type { Pokemon } from "#field/pokemon";
 import { getOrdinal } from "#test/test-utils/string-utils";
 import { isPokemonInstance, receivedStr } from "#test/test-utils/test-utils";
 import type { TurnMove } from "#types/turn-move";
+import type { AtLeastOne } from "#types/type-helpers";
 import type { MatcherState, SyncExpectationResult } from "@vitest/expect";
 
 /**
- * Matcher to check if a {@linkcode Pokemon} has used a specific {@linkcode MoveId} at the given .
+ * Matcher to check the contents of a {@linkcode Pokemon}'s move history.
  * @param received - The actual value received. Should be a {@linkcode Pokemon}
- * @param expectedValue - The expected value; can be a {@linkcode MoveId} or a partially filled {@linkcode TurnMove}
+ * @param expectedValue - The {@linkcode MoveId} the Pokemon is expected to have used,
+ * or a partially filled {@linkcode TurnMove} containing the desired properties to check.
  * @param index - The index of the move history entry to check, in order from most recent to least recent.
  * Default `0` (last used move)
  * @returns Whether the matcher passed
@@ -18,7 +20,7 @@ import type { MatcherState, SyncExpectationResult } from "@vitest/expect";
 export function toHaveUsedMoveMatcher(
   this: MatcherState,
   received: unknown,
-  expectedResult: MoveId | Partial<TurnMove>,
+  expectedResult: MoveId | AtLeastOne<TurnMove>,
   index = 0,
 ): SyncExpectationResult {
   if (!isPokemonInstance(received)) {
@@ -56,8 +58,8 @@ export function toHaveUsedMoveMatcher(
     pass,
     message: () =>
       pass
-        ? `Expected ${pkmName}'s ${moveIndexStr} NOT to match ${this.utils.stringify(expectedResult)}, but it did!`
-        : `Expected ${pkmName}'s ${moveIndexStr} to match ${this.utils.stringify(expectedResult)}, but got ${this.utils.stringify(move)}!`,
+        ? `Expected ${pkmName}'s ${moveIndexStr} to NOT match ${this.utils.stringify(expectedResult)}, but it did!`
+        : `Expected ${pkmName}'s ${moveIndexStr} to match ${this.utils.stringify(expectedResult)}, but got ${this.utils.stringify(move)} instead!`,
     expected: expectedResult,
     actual: move,
   };
diff --git a/test/test-utils/matchers/to-have-weather-matcher.ts b/test/test-utils/matchers/to-have-weather-matcher.ts
index 7bc9fe52bbc..b2f88e805c0 100644
--- a/test/test-utils/matchers/to-have-weather-matcher.ts
+++ b/test/test-utils/matchers/to-have-weather-matcher.ts
@@ -1,6 +1,6 @@
 import { WeatherType } from "#enums/weather-type";
 import { isGameManagerInstance, receivedStr } from "#test/test-utils/test-utils";
-import { toReadableString } from "#utils/common";
+import { toTitleCase } from "#utils/strings";
 import type { MatcherState, SyncExpectationResult } from "@vitest/expect";
 
 /**
@@ -38,9 +38,9 @@ export function toHaveWeatherMatcher(
     message: () =>
       pass
         ? `Expected Arena to NOT have ${expectedStr} weather active, but it did!`
-        : `Expected Arena to have ${expectedStr} weather active, but got ${actualStr}!`,
-    actual: actualStr,
-    expected: expectedStr,
+        : `Expected Arena to have ${expectedStr} weather active, but got ${actualStr} instead!`,
+    actual,
+    expected: expectedWeatherType,
   };
 }
 
@@ -54,6 +54,5 @@ function toWeatherStr(weatherType: WeatherType) {
     return "no weather";
   }
 
-  // TODO: Change to use updated string utils
-  return toReadableString(WeatherType[weatherType]);
+  return toTitleCase(WeatherType[weatherType]);
 }
diff --git a/test/test-utils/string-utils.ts b/test/test-utils/string-utils.ts
index 6dcb7438f96..827461d2491 100644
--- a/test/test-utils/string-utils.ts
+++ b/test/test-utils/string-utils.ts
@@ -104,7 +104,7 @@ export function stringifyEnumArray<E extends EnumOrObject>(obj: E, enums: E[keyo
 }
 
 /**
- * Convert a number into an English ordinal.
+ * Convert a number into an English ordinal
  * @param num - The number to convert into an ordinal
  * @returns The ordinal representation of {@linkcode num}.
  * @example
@@ -129,6 +129,11 @@ export function getOrdinal(num: number): string {
   return num + "th";
 }
 
+/**
+ * Get the localized name of a {@linkcode Stat}.
+ * @param s - The {@linkcode Stat} to check
+ * @returns - The proper name for s, retrieved from the translations.
+ */
 export function getStatName(s: Stat): string {
   return i18next.t(getStatKey(s));
 }