Xenk, Paladin Unbroken

Double strike
Auras you control have exalted. (Whenever a creature you control attacks alone, it gets +1/+1 until end of turn for each instance of exalted among permanents you control.)

Rohgahh of Kher Keep

At the beginning of your upkeep, you may pay {R}{R}{R}. If you don't, tap Rohgahh of Kher Keep and all creatures named Kobolds of Kher Keep, then an opponent gains control of them.
Creatures you control named Kobolds of Kher Keep get +2/+2.

Ragnar

{G}{W}{U}, {T}: Regenerate target creature.

Themberchaud

Trample
When Themberchaud enters, he deals X damage to each other creature without flying and each player, where X is the number of Mountains you control.
You may exert Themberchaud as he attacks. When you do, he gains flying until end of turn. (An exerted creature won't untap during your next untap step.)