Titania, voice of Gaëa

Reach
Whenever one or more land cards are put into
your graveyard from anywhere, you gain 2 life.
At the beginning of your upkeep, if there are
four or more land cards in your graveyard and
you both own and control Titania, Voice of Gaea
and a land named Argoth, Sanctum of Nature,
exile them, then meld them into Titania, Gaea Incarnate.