New Empyrean seems a noticeable boost from the old version. The new auto stun is neat as is the choice to take more damage and not be stunned. I think most characters of a high enough level to fight this guy will almost always take the damage....but if its two hits together....yeah I might take the stun over 42 extra damage just depends on which character gets hit.
Also noting he got a massive boost to his Int and Cha saving throws, so you can no longer take this guy out with a gimme banishment or something like that.
Honestly the only thing for me that missing (and its a minor thing) is some basic like Regeneration 10 kind of thing (or even just cure wounds as an at-will). It basically has no impact to the actual combat against high level characters, but to me it helps reinforce the power of these extremely high CR threats.
Even 500 completely untrained archers with shortbows can do about a quarter of the empyreans health in a single round. Now he likely can move away...but the damage is technically permanent until maybe a 1 hour short rest, and so you could see even a rag tag army actually chasing away one of these epic threats. But even just a bit a regen, and yeah he moves away for a few minuts, and comes back and full strength. Gives a lot more credence as to why you need heroes to beat these kinds of threats rather than just ragtag armies.
