Shal'thagar, The Fallen

Flying, trample, deathtouch
Territory (As long as you have exactly 25 life,
whenever Shal'thagar enters the battlefield, exile a
swamp and establish Shal'thagar's territory. You
may only have one territory established at a time.)
As long as a Shal'thagar has a territory
established, damage isn't removed from other creatures during the cleanup phase, players can't
gain life, and it gains indestructible.