nevermind
I just scaled damage inside the Armor::OnDamage function
here's the full code if anyone ever needs it:
function Armor::Damage(%this,%obj,%sourceObject,%position,%damage,%damageType)
{
if(%obj.client.getClassName() $= "GameConnection")
{
%scale = %this.maxDamage / $MonsterRPG::Data::ID[%obj.client.bl_id,maxHealth];
%damage *= %scale;
return parent::Damage(%this,%obj,%sourceObject,%position,%damage,%damageType);
}
}