While the 3/3 body for 3 mana isnt exciting, Lord Skitters ability to create a rat token every turn can quickly get out of control, especially against decks that are light on interaction, like ramp
Partner (You can have two commanders if both have partner.) Double or nothing. Illustrated by Mathias Kollros Standard Not Legal Alchemy Not Legal Pioneer Not Legal Historic Not Legal Modern Not Legal Brawl Not Legal Legacy Legal Comp
Diamond City surge foil $5 Being in the Fallout set, youre pretty safe from reprints
If you get a meld pair into play, youre likely winning the game very soon
If more "cantrips" (cards that replace themselves) were costed this aggressively, more of them would have been on this list
If both these effects arent enough, Palantir of Orthanc deals damage based on the mana value of the milled cards