Flamestrike
Legend
The monk won initiative and easily covered a hundred feet's distance to stunlock the archdruid. She never gets to take a single action.
No attacks of opportunity on the way in? Those meat shields (death knight and blackguard) need a speaking to!
For the record, seeing as the Diviner went directly after the Monk, is there any reason he didnt spam Wall of Force to encirle the other PCs and lock them down [letting the NPCs tear apart the Monk at their lesiure]?
I'm unsure if he has it or not. I would have given it to him.
Just seems like your NPCs (all of whom have long range AOE spells and high level effects) didnt bother to use them. I personally would have dumped at least three fireballs on the party on round 1. The Diviner and the Warlock both have AOE (and both went directly after the Monk, and were unstunned) yet somehow despite all the high level spells (between them) they did only 30 points of damage to the Monk.
I dont have a list of the spells (and abilities) the Diviner and Warlock have at their disposal, but that sounds fairly weak.
The Death Knight has AOE as well, and on his turn he just kind of ran towards the party for some reason instead of lobbing a Hellfire ball at the three dudes that just emerged from the town hall.
Also; how come the Archdruid was out of commission for two rounds? The Monk won initiative and ran 100' (presumably via the Ki dash action as a bonus action) and stunned him on round one (landing one or two of his two available attacks, with the Druid also failing his con save).
On round 2 the Monk ran 70' to the Diviner and stunned him (presumably again using the Ki dash action) with one of his two available attacks this turn. This means the Druid loses only one round, and should have been able to act on round two.
Did your bad guys have any lengthy duration buffs (concentration or otherwise) spells cast pre battle?