gargoyleking
Adventurer
I say shortened 2. Harb would gladly 'betray' the Thayans, mainly as he decided they were frenemies at the best and likely backstabbers as a standard.
I'll move him up while he's casting and start him 60 feet closer than where the group first observed the carnage. (Same with Myrral, but he can go a LOT further. On the other hand, I will probably start HIM from a hidden position, so maybe only a bit further. Hide rather than Dash, unless @Neurotic objects?)How far away is the PCs from the fighting Yuan-Tis? Chrysagon needs to get close and personal too.