Nihil, The Æther

Indestructible, Ward {5}
As long as your life is less than half your
starting life total you may cast Nihil the
Æther for {w}{w}{u}{u}{b}{b}{r}{r}{g}{g}
When nihil enters the battlefield, if it wasn't
cast, sacrifice it and all lands you control.
When Nihil deals combat damage to a
permanent, exile that permanent.
When Nihil deals combat damage to a player,
their life total becomes 1, end the turn.