Liam, World Breaker

Deathtouch, Devoid, Indestructible, Intimidate, Myriad
Pay two life, Target player sacrifices a permanent, then exile a card from that players Graveyard.
Pay four life, Target player exiles the top four cards of their Library.
Pay X life, put target permanent with CMC X onto the battlefield from exile, transform Liam.
Liam, World Breaker's power is equal to the number of cards in exile and Liam's toughness equal to that number plus one.