Cecil is our Honorable Mention, though, because he's almost good enough for a few categories
You would think Teferi, Time Raveler makes you want to play the Crashcade deck with Fury, Bonecrusher Giant, and Fire to try and clear the planeswalker, but my experience has been that Teferi is a three-drop sorcery against your free answers out of Living End
With him out, the plague does not stop coming
If Clever Impersonator enters the battlefield as a copy of a planeswalker, it will enter the battlefield with a number of loyalty counters on it equal to the loyalty printed in the lower right corner of the planeswalker card
Shapeshifters with Changeling are vampires, soldiers, humans, slivers, and much more, benefitting from everything that helps those creatures