Make unnerve less effective

src/data/ability.ts

@@ -2171,10 +2171,13 @@ export class DoubleBerryEffectAbAttr extends AbAttr {
 
 export class PreventBerryUseAbAttr extends AbAttr {
   apply(pokemon: Pokemon, passive: boolean, cancelled: Utils.BooleanHolder, args: any[]): boolean {
+    if (!Utils.randSeedInt(2)) {
       cancelled.value = true;
-
       return true;
     }
+    
+    return false;
+  }
 }
 
 export class RunSuccessAbAttr extends AbAttr {