Basing bot behaviours on neural networks / genetic algorithms shouldn't be too hard TBH.
Give the bot some fitness factors, damage done / damage taken / deaths / time since last damage dealt.
Give the bot some basic pathfinding, projectile, and sound identification routines.
Allow the bot to learn against "traditional bots", then against humans.
I linked these not so long ago, but they're fun to watch, so I'll link them again.
https://www.youtube.com/watch?v=qv6UVOQ0F44
https://www.youtube.com/watch?v=xOCurBYI_gY
Literally minutes of learning and entertainment.