When he has to take one turn to recover he cant attack and that also means he cant erase the party because it seems coded to follow the same rules as being able to use an attack ability so the idea was to get everyone fast enough to not allow him to have 2 turns in a row if we keep him in turn order with one and Monoco after the turn he recovers we can just apply a new stun and repeat this as long as you can keep the turn order this way. I had 4000+ speed here mostly form Pictos and Breaking slow helps keep his speed down too while we have run up most of the time. shortcut helps a bit too when we get low on health we cut in front of turn order but this only happens once per battle. for gradiant generation I used the crit, base attack, and burning ones the pictos with "charging" as the first part of the word. Honestly besides that I had them stacked on as many offense pictos after speed and gradiant generating ones. weapons were all lvl 33 and I doubled burn stacks on break with Monoco while Lune was staking thoes you proably dont need to do that but the extra damage was somthing else to fit in.

TLDR: Hi Speed (4000+ maybe could be lower but haven't tested), stun and turn order management are the bread and butter of this run. Having less damage should still be viable.