Nafargoliath, The Flying City

Indestructible, Hexproof
When Nafargoliath, The Flying City enters the battlefield, exile all land you control.
When a land enters the battlefield under your control, exile it instead insted.
{t} add {x} mana of any color plus two to your
mana pull, where {x} is the number of land cards exiled with Nafargoliath, The Flying City.
If {x} is more then twenty, when you tap Nafargoliath, The Flying City, you win the game.