Since there were not many battle guides for the challenges on Youtube I've decided to dedicate a series to it!
Score Modifiers for this challenge:
Finish in 28 actions (15,000)
Nuclear Attacks x4
Yusuke Takedowns x7
The strategy overall for this fight is to max out your baton passes and have Yusuke target the Demons with Nuclear weaknesses at full power. I recommend bringing Sleep/Dizzy vials for the later rounds as it's easy to get wiped out.
Make sure to equip an atom ring on Yusuke and to bring the right Personas (Shiki-Ouji & Shiisa) to target nuclear attacks and to null physical damage. I also would suggest bringing Izanagi for his God Maker trait.
Let me know in the comments if you would appreciate a Level 30 guide!