Sol'kanar the Swamp King

In Commander, Sol'kanar the Swamp King sits in a narrow lane: he either leads a Swamp-tribal or drain-life build, or slots into the 99 of black-heavy lifegain and drain decks where his passive triggers constantly. The swampwalk ability is irrelevant in most pods but becomes a guaranteed kill condition the moment an opponent plays mono-black or heavily black — a meta read worth making before sleeving him up. In Legacy and Vintage he's legal but sees no competitive play; a five-mana 5/5 with conditional evasion doesn't compete with what those formats are doing on turns one through three. Oathbreaker is his best non-Commander home if you want the drain trigger as a recurring engine under a black planeswalker signature spell shell.