First attempt at an endless run, did pretty well but I didn't realize there's no more aurite after loop 3 so i was stuck with second form Pyris. The main strategy for me was to go all out on karakai, because it's moonbeam is super powerful and I managed to fuse a circlet of Acuty on it as well IN ADDITION to Chip's Replica which gave it another one, which meant it could do moonbeam three times. This meant basically neverending damage, which basically carried the run along with a few healing tomes I picked up, healing the team over and over. Finally, Chip's Alchemize ability, which I hadn't used in a while due to a (perceived) bug where the bonus stats didn't seem to show up, very likely boosted my monsters' stats in the long run.
One thing that was really nice was that the extra space on the Karakai (so that Chip's Replica would work) allowed me to keep an extra item after the boss fight, which I could later sell for more aura in the next loop, basically replacing that greater blessing that allows me to keep 200 aura each loop.