Shouldn't be too hard. Just hook the Damage event, check and change it there, yeah?
Quote:
Syntax:
register_event ( const event[], const function[], const flags[], [ cond=[], ... ] )
Code:
register_event("Damage", "on_Damage", "b", "2!0")
EDIT:
Ok..it depends on if the damage is applied immediately and you only get the ass end of the routine...or if the hook is put at the END of the damage routine..but before it's applied. If it applies before the event hooks it...then it might be doable with fakemeta forward FM_Think or FM_PlayerPostThink.