I understand how S-E keeps going "regen, regen, regen, lulz" at us over and over.
Is this some kind of communications error, perhaps? Are they referring to "regen" as in "the ability for AV to recover it's 2-hour abilities at high speeds, thereby meteorfucking/chainbenedictioning us in the ass"?
If SC's (and possibly spells) of a specific element slow AV (that is, ones that match the day), then perhaps incorrect ones act as an accelerator, with AV going in spam mode after too much?
Matsui: First, defeat as many summons from Jailer of Love as you can: Ru'phuabo, Qn'xzomit, and Qn'hpemde. Absolute Virtue has a strong Regen effect, but if you defeat a lot of monsters it will be cut in half. After that, continue fighting using skillchains and magic that match the current day. (For example, Fireday ? Fire) This will eliminate the remaining half of his Regen effect. From there on out, it's up to you.
In other words, it's Fireday, you keep belting him with Liquification SC's and piling on the Fire spells ONLY- not even Fusion/Light SC's to be safe. Pile enough of these on and AV's ability to recover 2-hours rapidfire goes bye-bye. Do the normal "let's spam WS'es/random SC's, lol" and AV charges up it's lazer and you die, she dies, everybody dies as usual. If that works, you try the same with Fusion and Light SC's.
Or (more likely) it's S-E being obtuse and Sundi and company are parked in the offices watching people kill JoL and wiping on AV, shedding tears of sadistic joy.