Round 6, Part 1
Cendrik unleashes a wave of flame that writhes through the room, destroying the trapped menu board. It briefly outlines a medium-sized invisible blob behind the menu board, but the unseen creature disintegrates into nothingness immediately. Cendrik moves back and down the steps slightly in case there are more threats.
The Astral construct runs up and around the stairs, into the library and between two of the stacks.
Xaanthios stays where he is. RexThaun runs up the stairs, swinging his sword, but it bounces off of the layers of magical protection against the caster. Melinda follows at his call, running into the pattern of glowing lights.
Round 6, Part 2
The lights moving in the air are very pretty. Rex and Melinda both stop to look around at them. Sierra backs up the stairs, moving away from RexThaun.
Spoiler: Will save against Rainbow Pattern
(Melinda can ID it, if she’s not distracted)
Rex & Melinda are both in it. There is no text stating that if you make your save, you are immune to it for the next 24 hours (as is present for other mind-effecting spells)…. So Will Save DC 19
Rex Will (1d20+7)[8]
Melinda Will (1d20+5)[8]
Rex AOO (1d20+13)[26] for (1d10+4)[6] plus (1d6)[1] electricity.
Fascination offers a second saving throw if a hostile creature is attacking, moving closer, etc. Sierra has not technically attacked Rex, and she's moving away, so I think Rex is not entitled to a second save.
Spoiler: Map & Status
=> Party