It stops an attacker, it removes a blocker, it can protect your stuff from a Wrath, yours or theirs, you can kill tokens, you can re-trigger etb effects or you can just say "nothing will be killing my Kaya this turn"
For use with the Dungeon Master's Guide
Judge promos: Limited-edition cards given to certified Judges, often featuring unique art or foiling, can reach four figures
Once cast (or if you just need it), this can be cast as a generally under-curve creaturehaving only two instants/sorceries/adventures in the graveyard makes this fine on-rate, and it just gets better from there, acting like a Bedlam Reveler
Compelled Duel Conciliator's Duelist Deadeye Duelist Deepchannel Duelist Deft Duelist Devoted Duelist Disciplined Duelist Duel Tactics Duel for Dominance Duelcraft Trainer Dueling Coach Dueling Grounds Dueling Rapier Duelist of Deep Faith Duelist of the Mind Duelist's Flame Duelist's Heritage Duelists' Convocation International (playtest) Dusk Legion Duelist Faerie Duelist Gadwick's First Duel Heart of a Duelist (playtest) Heartflame Duelist Heartflame Duelist Jawbone Duelist Keen Duelist Killian, Ink Duelist Kor Duelist Lich's Duel Mastery (playtest) Mage Duel Midnight Duelist Mirri, Weatherlight Duelist Obyra, Dreaming Duelist Rivals' Duel Spiraling Duelist Squall, Gunblade Duelist Trueheart Duelist Voldaren Duelist Zulaport Duelist