The possibilities for degenerate play lines here are endless: you can drop huge threats, funnel mana into win conditions like Helix Pinnacle, or just give your creatures pseudo-vigilance by using the ability post-combat
Since the permanent is a creature and not a planeswalker, it can't be chosen as a target when your opponent declares attackers, and it won't leave the battlefield if it runs out of loyalty counters
This is the ultimate troll deck - it is absolutely hilarious and a blast to play
Sorin, Grim Nemesis is a great bomb, and you need to be running Ghostly Prison + Propaganda , and perhaps Collective Restraint or Sphere of Safety, even with 1 or 2 land types or enchantments, they are very useful and keep people off of you
1 Mavren Fein, Dusk Apostle