you need to use it on OPPONENTS monsters, and they need to be equal or LESS then your LP
While it still has a sunk-cost problem like Hearthstone , the decks are a bit cheaper than Hearthstone decks, which means even though you are technically throwing away money forever when you buy a deck, you're throwing away less of it
Trade and Complete Your Set: Once youve pulled your top cards, connect with other players and collectors to trade rare or duplicate cards
Casting Cost: Card Type: Legendary Creature - Phyrexian Horror Power / Toughness: 5 / 4 Card Text: If a source you control would deal noncombat damage to an opponent or a permanent that an opponent controls, it deals double that damage to that player or permanent instead
Once per turn, during this card's owner's Main Phase (Quick Effect): You can give control of this card to your opponent, then you can change this card's Attribute to any Attribute until the end of the next turn