She attempted to kill the Archive by letting the Hobs loose in a train station. Kidnapped Molly and brought her to Arctis Tor and let the Scarecrow dine on her. Set the fetches on the movie theater owner just to get Harry's attention. Tortures Slate to madness.
Kidnapped Molly, this was at the time when Maeve was Nfected & Arctis Tor was recently attacked in PG, not sure what the entire picture is actually like but it sounds like a manipulation to put Molly & Harry together, which Michael said "Maybe this was about getting Molly to protect you, Harry", which might points to not just Mab but also Uriel, as Mab conveyed she worked with Uriel in the aftermath of SF.
Mab also sent Harry to save the Archive if the Hobs failed in that book (SF). It's cold blooded manipulation, but as I pointed out in the other thread, Uriel also manipulated Harry at the risk of his mortal soul, no regret no admission & yet he's not consider a villain by Harry, Jim or readers.
Slate was directly involved in Nfected Maeve scheme, he betrayed Winter. If that punishment is out of ordinary for Winter Court, then maybe it's a villainous act, but was it? I don't think so.