The players have a chance to cure the plague that has sprouted up upon their travels. Will they choose to do the right thing and help bring health back to the region?
Hidden above an alcove behind a forgotten waterfall could be one of the last intact temples of a long persecuted religious order dedicated to the worship of their water elemental patron.
To be used for the final encounter, find the final treasure, or anything that needs to be hidden away better then normal. Typical “who the heck would ever spend the time making it” but it is fun and a mental challenge for a change.
Basq doesn't exist. He occupies a point in space--a single X,Y,Z point in the Cartesian plane, but he's not made of anything. People looking at him see whatever they want to see. Or what he wants you to see. Usually a mix. Just the same, he cannot be hurt swords or arrows. Only things that deal damage to an area (fireballs, gases) can damage him. Or weapons that can cut through an infinitely small point.