This is called "Decking Out", and that player loses the Duel
His other attacks are just okay, he's got a nice big HP pool, and his support effect halves the HP of both players
The main line of play is to use temporary steal spells like Act of Treason, attack the player with the highest life total, sacrifice that creature, then gain permanent control of it at the end of the turn
No matter which method you use to sell your bulk Pokmon cards, be sure to do your research
You can only activate 1 "Card of the Soul" per turn
So as long as development tested the Rats in high numbers to make sure it wasn't degenerate, we knew it was safe to break the rule (well, as safe as development can ever be the real world just has so many more playtesters.) Rule #4 Breaking Rules Is A Test For the Future When we do choose to break a rule, R&D tends to keep an eye on the card