Evo Magneto

If you have a base arms equipped, transform it into this, then equip this. (Put it under this in your arms zone.)
When this defends, you may destroy a card under it. If you do, gain control of target item with cost 0 or 1 controlled by the attacking hero.
Temper (When the combat chain closes, if this defended, put a -1{d} counter on it, then if it has 0{d}, destroy it.)