Kaho, Minamo Historian

Commander is where Kaho, Minamo Historian actually lives — the singleton format rewards the tutor effect built into the enter-the-battlefield trigger, and the multiplayer pace gives you enough turns to recoup value from the exiled spells. In Legacy and Vintage, a four-mana 2/2 that does nothing until it untaps is too slow; those formats want interaction on the stack before turn two, not a creature that telegraphs your entire instant suite to the table. Modern has the same problem compounded by the absence of the high-impact one-mana instants that make Kaho's exile pile dangerous. Oathbreaker is a reasonable niche fit if the signature spell is an instant, since Kaho can cache it for repeated access — unconventional but functional.