Innistrad: Crimson Vow previews just started, and one of the first cards to be previewed looks to be a very powerful one. Sorin the Mirthless does a lot of things we want in a planeswalker; gives you card advantage, as well as protects itself, in this case by creating a 2/3 flying lifelink that you can use to block as well as attack.
One thing that has always made some of the best planeswalkers the best planeswalkers is their ability to practically singlehandedly win the game. Jace, the Mind Sculptor, Oko, Thief of Crowns, Teferi, Hero of Dominaria and Elspeth, Sun’s Champion often didn’t need much help from anyone else. I’m not saying Sorin will be quite on a level with those cards, but it does look very strong.
The natural knock against Sorin the Mirthless is the drawback from the plus one, similar to a Dark Confidant effect. However, Sorin has an optionality clause. If the card costs too much, or you just can’t afford the life, you can still plus Sorin. Of course, the synergy between making 2/3 flying lifelinkers and paying life is pretty apparent. If you’re able to plus Sorin once and create a couple lifelinking attackers, you should be able to amass a fair amount of life to keep gaining advantage.
Sorin’s ultimate looks pretty strong as well, effectively as a 13-point drain. This will often be enough to finish off the opponent, or if not, perhaps a way to gain back a lot of life that was lost upticking Sorin to get to the point of ultimate. Sorin definitely looks strong, same as the last Sorin that was legal in Standard, in Vampire-based strategies. Not a lot of cards have been previewed as I’m writing this, but it will be interesting to see if there are a lot of synergies for Vampires that could also increase the potency of the 2/3 flying life linker, which is a Vampire.