Favor of Jukai

In Commander, Favor of Jukai is a role-player in Simic or mono-green decks that build around +1/+1 counters — commanders like Skullbriar, the Walking Grave or Zaxara, the Exemplary make good use of a permanent stat boost that also punches through chump blockers. In Pauper it fits aggressive green stompy lists that want cheap, lasting pump rather than a one-turn trick. Modern and Legacy have enough efficient threats and interaction that a single-target counter spell rarely competes for a slot, so Favor of Jukai stays on the bench there. Oathbreaker mirrors the Commander dynamic closely — if your planeswalker and signature spell strategy involves combat, it's a fine one-drop consideration.