Obeka, Splitter of Seconds | Illustration by Ryan Pancoast Unique is a pretty broad term, but Im looking for two things here: commanders that do something that nearly no other commander does, or commanders that encourage you to build off-beat decks or play underrepresented cards that you wouldnt play in a typical deck
Crystal Skull, Isu Spyglass In a deck full of artifact lands, Crystal Skull, Isu Spyglass does a really good impression of Mystic Forge for colored artifact decks
On the other hand, if your opponent is very aggressive, and you can count on your opponent always playing the most powerful spell at the first opportunity, this might be an opponent you can use permission spells to good effect against
That creature gets -4/-4 instead if you control a creature named Bogbrew Witch
Most of them aren't much to write home about, and then you have Fable of the Mirror-Breaker, which also broke multiple formats