Riryoku Guardian

If your LP are lower than your opponent's: Target 1 monster you control with "Gate Guardian" in its original name; halve your opponent's LP, then that monster gains ATK equal to your opponent's LP. You can banish this card from your GY; add 1 of your "Sanga of the Thunder", "Kazejin", or "Suijin" that is banished or in your Deck to your hand. You can only use each effect of "Riryoku Guardian" once per turn.