I did it with this team: Joker, Aldo, Gariyu, Mona, Amy, Soira. If I remember correctly, first three were with T2 fire grasta, Mona with max mp regen and Soira with fire resist neck and HP grasta. I didn't use AF, killed it with normal fire attacks. Just needed to keep an eye for Gariyu's shield and Mona's debuff. Soira and Amy were in reserve all the time. I used Soira before 2xST attack to swap with Mona, so Mona had 1 turn to breath and regen mp per each cycle. Amy is my light pillar, so she has high HP and I simply used her to tank 1 turn when needed (like that heavy AoE in the second phase etc). The fight could be easier with Myui or Guildna maybe, but I don't have them...