Arkus, Flame Unleashed

+3: Deal damage equal to half of Arkus, Flame Unleashed's loyalty to all other players and all creatures and planeswalkers those players control.
-5: Arkus gains loyalty equal to the number of creatures on the battlefield. Then, summon an X/X Dog with Rush, where X is the loyalty gained.
-20: Destroy all other permanents, then summon X X/X Dogs with Rush, where X is the number of permanents destroyed this way.