You may declare that a character is going on a quest
In a set with a bunch of lands that can turn into creatures, giving yours a boost can help give you the advantage over your opponents
The "Power Nine" are Ancestral Recall, Black Lotus, Mox Emerald, Mox Jet, Mox Pearl, Mox Ruby, Mox Sapphire, Timetwister, and Time Walk
TEFERI, MASTER OF TIME Master of Time breaks the rules for walkers in such an interesting and powerful way that I think everybody first underestimated, then wildly overestimated his power
See the future and cast miracles with Miracle Worker, fill your graveyard and reanimate monsters with Death Toll, cast tricky instants and mysterious face-down cards with Jump Scare!, or control monstrosities and make your opponents pay with Endless Punishment
They don't do anything, but some players quite enjoy having SpongeBob, Groot, Bonesy, Pink Pony, Ace the Bat-Hound, and others by their side