Even if the spell had been concealing you from the lich had worked, it definitely wasn't anymore. Taking a step back he begins casting a spell. Extending his arm, a bolt of electricity arcs from his fingertips at the woman who just attacked him, and arcing towards others within rang. As soon as the lightning fades away he lifts his other hand and fires five violet orbs of energy from his hand at the woman as well.

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Five foot step back, cast Chain Lightning, swift action Quickened Magic Missile

I'm assuming that Devrin and Marson are close enough that Chain Lightning can arc to them if they were close enough to be able to move up to and attack the lich on their turn (fairly certain they were within 30 ft). If they aren't keep in mind they are over 30 ft away when you start your turn. I'm also assuming that since Alicea and Agyen have little reason to be close that they're far enough away to not be hit by it.

DC for chain lightning is 22, 20 for the secondary targets (so Marson and Devrin).
Chain Lightning Damage (reduce by half if you make your save)
(11d6)[38]

Magic Missile Damage (All are being directed towards Shion)
(5d5+5)[19]