This normally isnt too much of an issue, but surprisingly mechanics like energy, transform, flashback and madness have never had their fair shots, achieving varying degrees of success
Wherever you have gigantic, powerful creatures with wild abilities, you'll see demand
Seedborn Muse and Vedalken Orrery are already annoying to play against because of how powerful they are, and Prophet of Kruphix combines those effects into one card
Loran of the Third Path Loran of the Third Path is a solid artifact killer and enchantment hater that gives you a card draw ability
The card's also seeing a little bit of play in Esper Self-Bounce decks, where it has a very similar function as in Modern
March of the Machine also gave us the Multiverse Legends sheet, which contained xxx/500 versions of assorted legendary creatures in a frame that reflected their home plane