Mother Gaia, Nature's Revenge

Trample
Mother Gaia, Nature's Revenge's Power and
Toughness are Equal to the Amount of Forests on
the battlefield.
During each end step, target land becomes a Forest
in addition to its other types.
At the beginning of your upkeep if all land on the
field are forests and you control a card called 'Finality, Downfall of Humanity' then you win the
game.