I actually did C9 and C10 with my previously mentioned communication mentions. However, I was pretty thorough about what to do in my messages. Here's my first message to my partner:

Hopefully, I got the right person. Ignore this message if it makes no sense to you and just reply something expressing that. Anyways, I'm running ASakuya, Orochi, Santakuya, LKali, and AYomi. You should bring a shield if it's Susano or DIzanami, depending on what color Sakuya team you run, but don't bring a shield in favor of some other well developed, useful subs. The goal is to triple gravity Illsix when he's under 56% health to deal with the resolve so make sure we save all Sakuya actives for Illsix; all binds in this dungeon are avoidable anyways. Zaerog will be a non-factor since I will be delaying him. Fl 1-3 we're basically just sweeping, but we have at least 2 turns (enemy monster turns, excluding pre-emps, meaning we can take 2 hits) on the 1st floor, 4 if we get a bit lucky with hearts; keep in mind that the 2nd hit is 31k. Six turns on Fl 2, hardest hit is about 40k when Defoud is under 30%, otherwise average hits are in the 20k range. First, 30k pre-emp, consider using a shield, then two turns on fl 3 before the overdamage absorb screws us. Fl 4 or Illsix, ideally, we 1 shot Illsix, trigger the 50% heal and 26k attack (shield would be good here if it wasn't used previously), then I triple gravity and kill. If Illsix is within our gravity range (55% health as I mentioned), and it's your turn, you must pass to me so I can triple gravity. Fl 5 or Zaerog, easy peasy, I'll delay when it's my turn. We wittle him down, then kill once absorb runs out, or even better, we get the right absorb and kill during delay while absorb is up.

I actually made a mistake on LiFive, and we actually only have 1 turn to kill.