His ultimate is hilarious. For -9 loyalty, you get a number of 1/1 black Vampire Knight tokens with lifelink equal to the highest life total among players. I can’t say this will be good in every game. But if you ever needed a finisher, this can definitely be one. And if for some reason that many tokens doesn’t win you the game, you can gain a lot of life.
The general consensus is that this is going to be a casual hit and a Commander all-star. That opinion seems well-founded. In Commander, he’ll be making plenty of tokens with that ultimate. Nevermind that his +1 hits all opponents, and Commander plays plenty of cards with high mana costs. You’d be silly not to play this if he’s in your colors. In casual play, he can be a big finisher and Vampire decks are super popular. So yeah, he’s going to be worth something no matter what.
But it remains to be seen if Standard can support another 6-mana planeswalker. The big draw of Elspeth Sun’s Champion is that she could make 3 tokens at will and her emblem was bonkers. Sorin, Grim Nemesis is powerful, as long as the deck is there to support him. Whatever the case, this is an awesome planeswalker.