So, I spent all of two days in the Halloween event.
Cleared out all the quests, bought most things of import from the shop, and beat the boss rush.
For the boss rush, my Team was Altera/Heracles/Waver/RW Jeanne/Mash/OG Cu. Front end was my normal beatsticks, back end was Team SNAFU. Jeanne is also a very good counter to Tamamo, and seeing as all I had left was a L38 Mash, the RW L80 Jeanne, and a L40 OG Cu, the fight took a very long time comparatively- 66 turns.