[Endoperez]

Item modding is severely limited. We can't add or even copy ITEM effects. Only change which weapon/armor an item refers to, if any. Weapon and armor modding is limited to causing damage or existing special effects available as weapons (paralyze, poison, entanglement, horror mark etc), and giving protection/encumberance for armor.

So "tattoo armor" is possible, but berserking, horror marking user isn't. The armor could have a weapon which horror-marks targets, but you can't make weapons target yourself.