Submarine Battleship Atragon

At the start of your first precombat main phase every
player reveals the top card of their library. If an opponent
reveals a land card, they must put in the graveyard or pay
{1}. If they reveal a non-land card, they take 1 damage. If
it is legendary, they take damage equal to Submarine
Battleship Atragon's power. If you reveal a land, you gain
1 life. If it is a non-land card, you can pay {3} to draw it.
If it is legendary, Submarine Battleship Atragon can't be
blocked this turn. Then ever