I would write a function like ```float Buffs_ZenAmmo(float ammo)``` that takes the amount of ammo used by a weapon and returns the modified amount, affected by Zen's buff power. Unfortunately, then you'd have to go over all ```w_<weapon>.qc``` files and look for access to each weapon's respective ```g_balance_<weapon>_ammo``` cvar, then wrap the ```cvar()``` calls into your ammo function.