Source: Arcana Unleashed
Level 2 Abjuration (Artificer, Bard, Cleric, Druid, Paladin, Ranger, Sorcerer, Warlock, Wizard)
Casting Time: 10 minutes or Ritual
Range: Touch
Components: V, S, M (a silk flag worth 100+ GP)
Duration: 1 hour
You create a magical dueling ground bounded by a glowing, rune-scribed circle in a 15-foot-radius Sphere centered on a point on the ground you touch.
As part of creating the dueling ground, you designate two willing creatures within the Sphere as the targets. The spell ends early if a creature other than one of the targets enters the Sphere.
If a target drops to 0 Hit Points while in the dueling ground, the target is Stable and teleports to the nearest unoccupied space outside the dueling ground. If a target is subjected to an effect that would kill it instantly without dealing damage while in the dueling ground, the target doesn’t die and instead has 0 Hit Points and the Unconscious condition, is Stable, and teleports to the nearest unoccupied space outside the dueling ground.
When only one target remains in the dueling ground, runes matching those on the ground around the Sphere briefly flash around the remaining target’s head like a crown.
Using a Higher-Level Spell Slot. You can target one additional willing creature for each spell slot level above 2.