Rei (2/5 EXR) vs Registeel | Legendary Arena | Pokémon Masters EX

lowered it to no extra energy. it was definitely possible without it, I just needed to make sure it is. sure enough, it did happen after 30 minutes of resetting.
You can get hit a few times in bar 3 if you avoid getting hit in bar 2, just needs a bit more RNG on arrow flinches.