Berserk Gene is implemented incorrectly

[FredrIQ]

Showdown sets Berserk Gene's confusion duration to last 256 turns. This is only accurate if either no Pokémon on that side has been confused, or the last confusion that happened was snapped out of. Specifically, what Berserk Gene does is to not actually apply a confusion duration, it just sets the confusion flag. Said duration is never actually updated when a Pokémon switches out, or is cured of confusion by means other than snapping out of it. Meaning that Berserk Gene will "inherit" the duration of the last applied confusion for that side of the field.

[Jethin10]

I’ve opened a PR that fixes this by clearing any existing confusion
volatile before reapplying it, ensuring a fresh duration via the
confusion onStart callback.

#11640

[Slayer95]

@FredrIQ please detail which part of your comment is the expected behavior, and which one is the current behavior.

[Jethin10]

@Slayer95 i have looked into the code by what i could tell it is currently Berserk Gene was making Pokémon confused without deciding how long the confusion should last, so it accidentally reused old confusion timers. My fix ensures confusion always starts fresh with a new, correct duration. I basically added a line so it it resets confusion counter

[FredrIQ]

@FredrIQ please detail which part of your comment is the expected behavior, and which one is the current behavior.

Expected behaviour: Berserk Gene confusion inherits the duration of the last confusion on the given side.
Current behaviour: Berserk Gene confusion always lasts for 256 turns.