Challenger

You’ve battled against countless of Enemies and always long for a battle against a worthy opponent. You gain the following psychic ability:

Challenge:

• Once every Long rest you can challenge a single enemy to a duel either by words, (such as insulting their honor) or by a gesture of your choice. The Challenged must then make a Wisdom saving throw. If the Challenged succeeds, Challenge fails and the Challenger takes 3 points of psychic ego damage.
• The moment Challenge succeeds, both the Challenger and the Challenged are locked in a duel. The Duel only ends, once one of the two opponents loses Consciousness, dies, or is unable to continue the duel in some other way. Once locked in said duel, both the Challenged and the Challenger are unable to take any other actions except actions that cause harm towards their duel opponent. This includes moving away from their opponent (they may move closer or further away as long as both have the strategic purpose of harming the opponent, such as getting distance first and then casting a spell afterward or getting into range for a grapple), attacking other enemies that aren't their duel opponent,  or Healing.