There are only two rules of tactics: never be without a plan, and never rely on it
Play Rule #13 states: Abilities which refer to other cards owned outside the game (Wishes, Spawnsire, Research, Ring of Ma'ruf) do not function in Commander without prior agreement on their scope from the playgroup. Therefore, Spike is twice banned in Commander, and even if Unstable were allowed, Spike wouldnt be able to be played
A Love Letter to the Magic: The Gathering Power 9 Theres a certain something in the hunt, isnt there
This is a solid option for any nontoken deck, but it's especially powerful in decks full of high cmc spells like Jodah, Archmage Eternal, Golos, Tireless Pilgrim, and Braids, Conjurer Adept
Those aside, sacrifice outlets for lands decks are pretty common, making Yuma essentially a three-mana commander in the right brew