Unkar, Leader of the Yoog

Flying, Trample, Hexproof
When Unkar, Leader of the Yoog enters the battlefield you must pay {6} or exile Unkar,
Leader of the Yoog
When an opponent casts a spell Unkar, Leader of
the Yoog deals damage to
the for each {w}, {u}, {b}, {r}, {g}, {b/g}, {b/r}, {g/u}, {g/w}, {r/g}, {r/w}, {u/b}, {u/r}, {w/b}, or {w/u} in its mana cost, then you
gain that much life.