Tian, Lich Wizard

Play with the top card of your library revealed.
As long as Tian is untapped you may play lands
and cast spells from the top of your library and
you don't lose the game for having 0 or less life.
Whenever Tian is dealt damage or you lose life,
exile that many cards from the top of your library.
Pay 1 life: Tian gains indestructible and hexproof
until end of turn. (You can't pay life below 0)