Playing with and against it is a nightmare. Its Speed is super customizable, ranging from the standard max Speed to sweep teams to bulkier variants outrunning specific threats like Pawniard and bulky variants of Gabite. Its offensive movepool is just as versatile, as even Shadow Ball can be switched to Hex on bulkier or status-heavy builds. As an offensive threat, any one of its coverage moves can threaten a Pokemon in some form: Draining Kiss makes it more threatening against Gabite, Sneasel, Murkrow, and Drakloak (the latter which has highlighted how dire and poor hazard removal is), Thunderbolt takes out Rufflet and better threatens Mareanie, Energy Ball covers other Quax, Frogadier, and Naclstack all at once...even something like Icy Wind gets a better hit on Dartrix. Perhaps most importantly, the utility choices feel nearly limitless - Will-O-Wisp nullifies any physical attacker, Thief capitalizes on the lack of item removal, Taunt shuts down Stealth Rock setters, Pain Split makes it near limitless in its usefulness. Even Night Shade takes advantage of the low HP most NFEs sport.
I think Misdreavus is pretty unhealthy, but not broken. While its raw stats alone aren't entirely oppressive, the versatility is. It can pretty much do anything it wants and be nearly guarantee to do something positively noteworthy for its team. There's a reason there's so much Misdreavus usage.
