Sesto can use 'Channel Divinity' for turning (DC 15) and destroying undead (≤0.5CR) but also heal any number of characters within 30ft up to half their maximum HP using a pool of 30HP.
I was hoping that the undead would be stuck in the store room and not come after anyone in the prison room. After all, the undead ignored the bad guys. Now it looks like they were programmed to attack intruders. But I doubt the bad guys have control over the undead, else why would they be in a different room with a portcullis between them? I can't recall if there was a cultist amongst the bad guys, can you?
Resources are precious. Sesto was hoping he could save his Channel Divinity for later. We could fight the undead but then Sesto might use his resources to heal party members instead.
Btw, I think these undead are special undeads with higher CR than 0.5 and thus could only be turned and not destroyed on a failed save. Also, a turned undead stops being turned if you attack it. The turning lasts a minute. I guess we could turn them and leave them be, then run out of the room and into another shutting the door behind us. The undead may follow us but will be stopped by doors or maybe even lose track of us. I don't know. They would probably just turn up at another point in time when it is most inconvenient for us. Better kill (hmm... destroy) them now.
Well, what to do? Shoving the one holding the portcullis and thereby trapping the crawlers could work. At least for a round or two until the undead continue their pursuit.
Does anyone else have any ideas?