Hey Zarel, I found a way to break the Endless Battle Clause. I'll post a replay of it at the end of this message. Respond to this message if you think this is Custom Avi worthy, because I heard you get those if you found ways to break the clause. In the replay, watch till turn 50, then skip to turn 145 if you want to skip a boring part and watch how I recover Fling's PP.
http://replay.pokemonshowdown.com/ou-300648619
http://replay.pokemonshowdown.com/ou-300648619