ZDoom

The strange behavior is because when a monster shoots you, that monster becomes your target, but it'll never change again, because your threshold gets set and that never decreases on players (it only decreases normally when A_Chase is called), so every time you would do a A_CustomMeleeAttack, you try to attack that single target like you're a monster.

Kinda reminds me of a fun and common dehacked thing where you gave the pistol the archvile attack function and it'd blow up the first thing that shot you. Not practical, but amusing for a few seconds

A_CustomMeleeAttack is a monster function, it does not work for players.

Sorry about that....
It does exhibit some strange behavior though.

You're not supposed to use [wiki]A_CustomMeleeAttack[/wiki] as a melee weapon attack. You want to use [wiki]A_CustomPunch[/wiki] instead.

This weapon hangs on the last monster it kills. This means that you cannot kill more than one monster!!