Ghostbuster/Mystara crossover
by Marc SaindonInspired a bit by the recent Glen Welch video asking to bring back the good necromancer, instead of lumping 'dark' as automatically 'evil', what if the characters are a group outcast initiates (Wizard from the necromancer school, Death and Grave domain clerics... or even College of Spirits Bards, Path of Ancestral Guardian Barbarian, Gloom Stalker and Horizon Walker rangers, Phantom Rogues) who try their luck at business ghost hunting in Karameikos? Mirros takes the place of New York as the urban hub of adventure, and Karameikos provides the Transylvanian backdrop for Ravenloftian tales, mixed in with Tim Burton's early movies (so not all undead with be hostiles, some just want to move on or even socialize).
Naturally, there is a story arch where an Entropic equivalent of Gozer is trying to breach into the world through the various rituals of a hidden Cult.
(pic from https://i.pinimg.com/originals/ab/49/eb/ab49ebcd0a32bd19e5fa98887aaf36f5.jpg)