diff --git a/src/phase-manager.ts b/src/phase-manager.ts
index e6e0b247405..3f465f7b5fb 100644
--- a/src/phase-manager.ts
+++ b/src/phase-manager.ts
@@ -400,6 +400,7 @@ export class PhaseManager {
    */
   private startCurrentPhase(): void {
     if (!this.currentPhase) {
+      console.warn("trying to start null phase!");
       return;
     }
     console.log(`%cStart Phase ${this.currentPhase.phaseName}`, "color:green;");
diff --git a/test/testUtils/phaseInterceptor.ts b/test/testUtils/phaseInterceptor.ts
index c196a74451a..03914c39d42 100644
--- a/test/testUtils/phaseInterceptor.ts
+++ b/test/testUtils/phaseInterceptor.ts
@@ -3,7 +3,7 @@ import type { Phase } from "#app/phase";
 import { UiMode } from "#enums/ui-mode";
 import UI from "#app/ui/ui";
 import type { PhaseString } from "#app/@types/phase-types";
-import { vi } from "vitest";
+import { vi, type MockInstance } from "vitest";
 import { format } from "util";
 
 interface PromptHandler {
@@ -16,7 +16,7 @@ interface PromptHandler {
 
 /**
  * The PhaseInterceptor is a wrapper around the `BattleScene`'s {@linkcode PhaseManager}.
- * It allows tests to exert finer control over the phase system, providing logging,
+ * It allows tests to exert finer control over the phase system, providing logging, manual advancing, etc etc.
  */
 export default class PhaseInterceptor {
   private scene: BattleScene;
@@ -44,16 +44,18 @@ export default class PhaseInterceptor {
    * Method to initialize various mocks for intercepting phases.
    */
   initMocks() {
-    const originalSetMode = UI.prototype.setMode;
-    vi.spyOn(UI.prototype, "setMode").mockImplementation((mode, ...args) =>
-      this.setMode(originalSetMode, mode, ...args),
-    );
+    const originalSetMode = UI.prototype["setModeInternal"];
+    // `any` assertion needed as we are mocking private property
+    const uiSpy = vi.spyOn(UI.prototype as any, "setModeInternal") as MockInstance<
+      (typeof UI.prototype)["setModeInternal"]
+    >;
+    uiSpy.mockImplementation(async (...args) => {
+      this.setMode(originalSetMode, args);
+    });
 
     // Mock the private startCurrentPhase method to do nothing to let us
     // start them manually ourselves.
-    this.scene.phaseManager["startCurrentPhase"] satisfies () => void; // typecheck in case function is renamed/removed
-    // @ts-expect-error - startCurrentPhase is private
-    vi.spyOn(this.scene.phaseManager, "startCurrentPhase").mockImplementation(() => {});
+    vi.spyOn(this.scene.phaseManager as any, "startCurrentPhase").mockImplementation(() => {});
   }
 
   /**
@@ -72,6 +74,7 @@ export default class PhaseInterceptor {
    * @param runTarget - Whether or not to run the target phase; default `true`.
    * @returns A promise that resolves when the transition is complete.
    */
+  // TODO: Does this need to be asynchronous?
   public async to(targetPhase: PhaseString, runTarget = true): Promise<void> {
     let currentPhase = this.scene.phaseManager.getCurrentPhase();
     while (!currentPhase?.is(targetPhase)) {
@@ -126,12 +129,13 @@ export default class PhaseInterceptor {
    * @param args - Additional arguments to pass to the original method.
    */
   private async setMode(
-    originalSetMode: typeof UI.prototype.setMode,
-    mode: UiMode,
-    ...args: unknown[]
-  ): ReturnType<typeof UI.prototype.setMode> {
+    originalSetMode: (typeof UI.prototype)["setModeInternal"],
+    args: Parameters<(typeof UI.prototype)["setModeInternal"]>,
+  ): ReturnType<(typeof UI.prototype)["setModeInternal"]> {
+    const mode = args[0];
+
     console.log("setMode", `${UiMode[mode]} (=${mode})`, args);
-    const ret = originalSetMode.apply(this.scene.ui, [mode, ...args]);
+    const ret = originalSetMode.apply(this.scene.ui, [args]);
     this.doPromptCheck(mode);
     return ret;
   }
diff --git a/test/utils/phase-interceptor-prompts.test.ts b/test/utils/phase-interceptor-prompts.test.ts
new file mode 100644
index 00000000000..b6397eb5200
--- /dev/null
+++ b/test/utils/phase-interceptor-prompts.test.ts
@@ -0,0 +1,106 @@
+import type { PhaseString } from "#app/@types/phase-types";
+import { globalScene } from "#app/global-scene";
+import { Phase } from "#app/phase";
+import type { Constructor } from "#app/utils/common";
+import { UiMode } from "#enums/ui-mode";
+import GameManager from "#test/testUtils/gameManager";
+import Phaser from "phaser";
+import { beforeAll, beforeEach, describe, expect, it, vi } from "vitest";
+
+abstract class mockPhase extends Phase {
+  public override readonly phaseName: any;
+
+  override start() {
+    this.end();
+  }
+}
+
+class testDialogueUiPhase extends mockPhase {
+  public readonly phaseName = "testDialogueUiPhase";
+  override start() {
+    void globalScene.ui.setMode(UiMode.TEST_DIALOGUE);
+    super.start();
+  }
+}
+
+class titleUiPhase extends mockPhase {
+  public readonly phaseName = "titleUiPhase";
+  override start() {
+    void globalScene.ui.setMode(UiMode.TITLE);
+    super.start();
+  }
+}
+
+class dualUiPhase extends mockPhase {
+  public readonly phaseName = "dualUiPhase";
+  override start() {
+    void globalScene.ui.setMode(UiMode.TEST_DIALOGUE);
+    void globalScene.ui.setMode(UiMode.TITLE);
+    super.start();
+  }
+}
+
+describe("Utils - Phase Interceptor Prompts", () => {
+  let phaserGame: Phaser.Game;
+  let game: GameManager;
+
+  beforeAll(() => {
+    phaserGame = new Phaser.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+    setPhases(testDialogueUiPhase, titleUiPhase, dualUiPhase);
+  });
+
+  function setPhases(...phases: Constructor<mockPhase>[]) {
+    game.scene.phaseManager.clearAllPhases();
+    game.scene.phaseManager.phaseQueue = phases.map(m => new m());
+    game.scene.phaseManager.shiftPhase(); // start the thing going
+  }
+
+  /** Wrapper function to make TS not complain about `PhaseString` stuff */
+  function to(phaseName: string, runTarget = false) {
+    return game.phaseInterceptor.to(phaseName as unknown as PhaseString, runTarget);
+  }
+
+  function onNextPrompt(target: string, mode: UiMode, callback: () => void, expireFn?: () => boolean) {
+    game.onNextPrompt(target as unknown as PhaseString, mode, callback, expireFn);
+  }
+
+  it("should run the specified callback when the given ui mode is reached", async () => {
+    const callback = vi.fn();
+    onNextPrompt("testDialogueUiPhase", UiMode.TEST_DIALOGUE, () => callback());
+
+    await to("testDialogueUiPhase");
+    expect(callback).toHaveBeenCalled();
+  });
+
+  it("should not run callback if wrong ui mode", async () => {
+    const callback = vi.fn();
+    onNextPrompt("testDialogueUiPhase", UiMode.TITLE, () => callback());
+
+    await to("testDialogueUiPhase");
+    expect(callback).not.toHaveBeenCalled();
+  });
+
+  it("should not run callback if wrong phase", async () => {
+    const callback = vi.fn();
+    onNextPrompt("titleUiPhase", UiMode.TITLE, () => callback());
+
+    await to("testDialogueUiPhase");
+    expect(callback).not.toHaveBeenCalled();
+  });
+
+  it("should work in succession", async () => {
+    const callback1 = vi.fn();
+    const callback2 = vi.fn();
+    onNextPrompt("dualUiPhase", UiMode.TEST_DIALOGUE, () => callback1());
+    onNextPrompt("dualUiPhase", UiMode.TITLE, () => callback2());
+
+    await to("dualUiPhase");
+    expect(callback1).not.toHaveBeenCalled();
+  });
+});
diff --git a/test/utils/phase-interceptor.test.ts b/test/utils/phase-interceptor.test.ts
new file mode 100644
index 00000000000..6e1422fa94a
--- /dev/null
+++ b/test/utils/phase-interceptor.test.ts
@@ -0,0 +1,126 @@
+import type { PhaseString } from "#app/@types/phase-types";
+import { Phase } from "#app/phase";
+import type { Constructor } from "#app/utils/common";
+import GameManager from "#test/testUtils/gameManager";
+import Phaser from "phaser";
+import { beforeAll, beforeEach, describe, expect, it } from "vitest";
+
+let phaserGame: Phaser.Game;
+let game: GameManager;
+
+abstract class mockPhase extends Phase {
+  public override readonly phaseName: any;
+
+  override start() {
+    console.log(this.phaseName);
+    this.end();
+  }
+}
+
+class normalPhase extends mockPhase {
+  public readonly phaseName = "normalPhase";
+}
+
+class applePhase extends mockPhase {
+  public readonly phaseName = "applePhase";
+}
+
+class oneSecTimerPhase extends mockPhase {
+  public readonly phaseName = "oneSecTimerPhase";
+  override start() {
+    setInterval(() => {
+      super.start();
+    }, 1000);
+  }
+}
+
+class unshifterPhase extends mockPhase {
+  public readonly phaseName = "unshifterPhase";
+  override start() {
+    game.scene.phaseManager.unshiftPhase(new normalPhase() as unknown as Phase);
+    game.scene.phaseManager.unshiftPhase(new applePhase() as unknown as Phase);
+    super.start();
+  }
+}
+
+// reduce timeout so failed tests don't hang as long
+describe("Utils - Phase Interceptor", { timeout: 4000 }, () => {
+  beforeAll(() => {
+    phaserGame = new Phaser.Game({
+      type: Phaser.HEADLESS,
+    });
+  });
+
+  beforeEach(() => {
+    game = new GameManager(phaserGame);
+    setPhases(normalPhase, applePhase, oneSecTimerPhase, unshifterPhase, normalPhase);
+  });
+
+  function setPhases(...phases: Constructor<mockPhase>[]) {
+    game.scene.phaseManager.clearAllPhases();
+    game.scene.phaseManager.phaseQueue = phases.map(m => new m());
+    game.scene.phaseManager.shiftPhase(); // start the thing going
+  }
+
+  function getQueuedPhases(): string[] {
+    return game.scene.phaseManager["phaseQueuePrepend"]
+      .concat(game.scene.phaseManager.phaseQueue)
+      .map(p => p.phaseName);
+  }
+
+  function getCurrentPhaseName(): string {
+    return game.scene.phaseManager.getCurrentPhase()?.phaseName ?? "null";
+  }
+
+  /** Wrapper function to make TS not complain about `PhaseString` stuff */
+  function to(phaseName: string, runTarget = true) {
+    return game.phaseInterceptor.to(phaseName as unknown as PhaseString, runTarget);
+  }
+
+  describe("to", () => {
+    it("should run the specified phase and halt after it ends", async () => {
+      await to("normalPhase");
+      expect(getCurrentPhaseName()).toBe("applePhase");
+      expect(getQueuedPhases()).toEqual(["oneSecTimerPhase", "unshifterPhase", "normalPhase"]);
+      expect(game.phaseInterceptor.log).toEqual(["normalPhase"]);
+    });
+
+    it("should run to the specified phase without starting/logging", async () => {
+      await to("normalPhase", false);
+      expect(getCurrentPhaseName()).toBe("normalPhase");
+      expect(getQueuedPhases()).toEqual(["applePhase", "oneSecTimerPhase", "unshifterPhase", "normalPhase"]);
+      expect(game.phaseInterceptor.log).toHaveLength(0);
+    });
+
+    it("should start all phases between start and target", async () => {
+      await to("oneSecTimerPhase");
+      expect(getQueuedPhases()).toEqual(["unshifterPhase", "normalPhase"]);
+      expect(game.phaseInterceptor.log).toEqual(["normalPhase", "applePhase", "oneSecTimerPhase"]);
+    });
+
+    it("should work on newly unshifted phases", async () => {
+      setPhases(unshifterPhase); // adds normalPhase and applePhase to queue
+      await to("applePhase");
+      expect(game.phaseInterceptor.log).toEqual(["unshifterPhase", "normalPhase", "applePhase"]);
+    });
+
+    it("should wait until phase finishes before starting next", async () => {
+      setPhases(oneSecTimerPhase, applePhase);
+      setTimeout(() => expect(getCurrentPhaseName()).toBe("oneSecTimerPhase"), 500);
+      await to("applePhase");
+    });
+  });
+
+  describe("shift", () => {
+    it("should skip the next phase without starting", async () => {
+      expect(getCurrentPhaseName()).toBe("normalPhase");
+      expect(getQueuedPhases()).toEqual(["applePhase", "oneSecTimerPhase", "unshifterPhase", "normalPhase"]);
+
+      game.phaseInterceptor.shiftPhase();
+
+      expect(getCurrentPhaseName()).toBe("applePhase");
+      expect(getQueuedPhases()).toEqual(["oneSecTimerPhase", "unshifterPhase", "normalPhase"]);
+      expect(game.phaseInterceptor.log).toEqual([]);
+    });
+  });
+});