Throne of Eldraine is starting to show some tools for graveyard decks in Feasting Troll King and potentially Lochmere Serpent, so we might be able to do something with Emrys enter the battlefield ability
The answer depends on how you define the rarest
They can't be the target of spells or abilities, their static abilities have no effect on the game, their triggered abilities can't trigger, they can't attack or block, and so on
If you're still unsure which to choose, Synchro of Unity is the best all-rounder deck and offers a playstyle somewhere in the middle of the two others
Depending on whether someones purpose is to buy cards, speculate on certain card values, or build a deck, the answer to the question Which card game is worth the most money
Wrap Up Kor Firewalker | Illustration by Matt Stewart Protection is a super powerful mechanic