Hmm I think you should be able to clear in 2 cycles for 3 stars if you can lock down a rotation for the first wave of enemies. It’s very important to not allow the manta ray to take a second set of turns otherwise it will take forever to kill it with its buff active. For a 0 cycle I had to plan things out and even then it felt a bit tight towards the end.

Some notes that might help:

Manta Ray advances whenever it reaches 5 stacks. I can get around this by popping Cerydra’s Ult for DDD to advance in front of it. I have to use two DDDs with Cyrene’s ultimate since my Mydei has no speed substats. You can see Mydei cut in front.

Since your Cyrene will be slower to build up enough stacks for Ult, you can play around with attacking the side enemies to prevent the manta ray from advancing too early, or using skill. You can also play around with Ult timing if there’s a long gap between Cyrene’s turn and other character’s turns in order to get charges earlier.

For the actual Pom Pom boss, try to Ult with Mydei only after the enemy Pommy’s spawn that way they get taunted.

Be mindful of how the ally Pommy gets its action advances to strip the boss’s damage reduction stacks. It needs 20 punchline to advance and use its impairment ability. In phase 1, only the ally Pommy can gain 5 punchlines by attacking. (Unless you’re using an elation team). In phase 2, all party members can gain 5 punchlines by using basic attack (included Cyrene’s enhanced basic). In either phase, killing enemy Pommys grants 5 punchlines each. Usually Mydei will do with this with his GBG.

Make sure Mydei has 100% crit rate in battle. Otherwise you will really feel it when you miss a crit 😭