[@KatherinWinter]You can use second panther for distraction. You can create physical shadow objects close to youself, why don't you create it in his skull? Your physical atack definetly can harm him, so go with hit-and run tactics. Claws don't affect her physically, that is ay he has to grab her with hands. He can't heal from energy he absorbs - it's just not enough of it to turn into flesh. Make him tired, make him suffer, make him give up the fight. You can use psychological advantages - Dennis is not quite stable which you can exploit. His detection abilities work around power cores - so create a few power beacons to break his attention. Fight is not about atacks only, there are tons of ways you harm your opponent. For example, i expected Roxy to freak out a little when Dennis turned into Cronenberg thing, but i can explain no reaction by the world of gods where such things are common. Go have fun with her abilities, i believe in your creativity, and rule of cool always works, at least for me)))