Sorin, Lord of Innistrad Not the best planeswalker and not the worst
Card Name Mana Cost Type Legendary Creature Human Villain Rarity Mythic Rare rules Text Baron Von Count enters with a doom counter on "5."Whenever you cast a spell with the indicated numeral in its mana cost, text box, power, or toughness, move the doom counter one numeral to the left.When the doom counter moves from "1," destroy target player and put that doom counter on "5." P/T Number 127 Language English Not Legal Formats Alchemy, Brawl, Commander, Competitive Brawl, Historic, Legacy, Modern, Pauper, Pioneer, Standard, Timeless, Vintage Rulings (1/19/2018) If a player is destroyed, that player loses the game
You'll be able to decide with your own Doctor Who decks
However, if you put this in a deck that can boost the power of Esper Sentinel - say, Humans in Modern - this is going to be a 2/2 or more, which means youre probably going to draw an extra card most turns
Plus, remember, we're ranking battles based on 60-card constructed formats where you can easily splash a color, not by Commander, where harsh color-identity rules make this impossible