The Bellatrix
The Bellatrix is a fearsome force – a female soldier, as is obvious from her name. Her model shows Hell’s attempt to mimic human norms. No doubt the Bellatrix was ordered to be a beautiful woman, and so searched earth’s archives to find the loveliest female form. Learning that a highly-rated example was the Venus de Milo, she has taken that form, at least as much as possible keeping in mind her need to be a warrior.
Of course the result is strictly grotesque. If you look close, you can see that each of the Venus’s stumps has an eye on it, so it is actually her head. Eww.
Berserkergang
Most of the 4th Circle demons have an ongoing effect that transforms the map in some way. The Hellhound and Catoblepas are good examples. Some upcoming 4th Circle demons are even better examples. (Just wait for the Hortator and the Philter!)
The Bellatrix can simply be avoided, if you’re willing to take the 4 Doom hit when she escapes. And you might want to consider this, because she has a toughness of 5, which is non-trivial, plus she rolls 4d12 in battle(!)
Fighting the Bellatrix
The real issue with the Bellatrix is that her Berserkergang ability means her attack is scored against ALL heroes in her area. This is quite a predicament for the heroes, because the usual way you knock out a 4th Circle demon is by ganging up on them. But if you gang up on the Bellatrix, you are falling into her trap, unless you think you can kill her in a single round, before she gets her attack off.
Unfortunately, with a Toughness of 5, this isn’t so likely. Even a 1d8 attack hits her less than half the time, and then she has 4 health. Plus of course there are other enemies in her chamber.
Anyway, I’ve seen the Bellatrix avoided perhaps more than any other 4th Circle demon, which means the players are reconciled to losing 4 Doom. I’ve also seen her killed of course, but more than once I’ve seen a major attack fail, after which the players were really sad when she lashed back at them.