Niarhet, Eternal dragon

Flying, indestructible.
The first time on each of your turns that you
would pay life, you pay 0 life instead.
(This reduces X life to zero).
If Niarhet would be placed into a graveyard, exile
it instead.
Niarhet was dead for so long, he has no life left to
give, yet he would still give it all to Hethrian.