Cannoness

Whenever you gain life, put a +1/+1 counter on Cannoness.
As long as Cannoness has four or more +1/+1 counters on it, it has flying and vigilance.
As long as Cannoness has ten or more +1/+1 counters on it, it has indestructible.

"By bolter shell, flamer burst and melta blast, the mutant, the heretic and the traitor alike are cleansed of their sin of existence. So has it been for five millennia, so shall it be unto the end of time."
—Sister Immaculata