Btw, their Greatest Fears? Are TOTALLY immune to their attacks and attempts, they regenerate from ALL damage dealt, in a REALLY obvious and flashy way.
Only a team member can help destroy another's fear.
I dunno. Part of the idea here is to face your fears, not be completely helpless and dependent on someone else to combat them for you. The idea is more that your teammates' presence helps bolster your courage enough that you can face your fear yourself.
I am thinking that I will give each PC a DC 20 Wisdom save to resist being frightened by the fear, perhaps even with advantage if the other PCs are being supportive and encouraging.
The question is: should the party face all of their fears at once, or should I just have them face on person's fear at a time? Or should it be one creature that appears differently to each PC?
EDIT: Something else I'm thinking about - either included in this quest or as a separate thing - is having a series of encounters that test characters' loyalty to the team. So far I've only thought of one that's based on a setpiece from
Diablo III. In an early stage of that game, there's a room with a glowing chest set on a circular block of stone. There are four more circular blocks of stone surrounding the chest. When you go to open it, the block spirals down under the floor, taking the chest with it, and a stone plug slides into place above. At the same time, plugs slide away from the other four circles, and blocks with necromantic banners on them rise up into the room. The banners then summon a bunch of skeletons into the room. They keep doing so until you've destroyed the banners. Once the last banner is destroyed, the central plug slides open again and the chest rises back into the room so you can loot it. Here's a
video.
Here's my thinking: A character goes to open the chest. It starts to sink slowly down into the floor while the banners rise up around it. As skeletons start to appear and attack the party, the character who went for the chest has a choice: do they try to get the chest and the treasure before it disappears under the floor, or do they forget about the treasure and help their friends defeat the skeletons? If they go for the treasure first and manage to get the chest open before it disappears, then all they find is junk, and the chest doesn't return once the skeletons are defeated.
If, however, the character who first tried to open the chest chooses to let it go and help the others fight the skeletons, then the chest returns afterwards with some worthwhile treasure in it.