It's pretty good, as said there's a lot of good descriptions of things and actually the strange setting and interaction between these two species or worlds was interesting. I like the Beelzebub character, he had a lot of attitude and there were moments I laughed at. "A terrible ailment of the bowels has struck him, so much so that he can hardly move from his bed." I could definitely imagine being spoken in a fantasy TV show.
All the characters are pretty flamboyant caricatures with fluffy language in places that maybe niggles me a bit, but that's probably a personal thing. I'm not a huge fan of fantasy anyway, especially when it revels in superficial elements like describing what people are wearing when it's actually irrelevant to what's going on. Description is obviously good when it's a world unlike anything we know, but I think describing exactly what people look like is something that I personally never remember through the rest of the story and it just slows down the reading process.
I guess a couple of other little specific criticisms from me are...
1) There were just a few lines of dialogue that I felt were unnecessary. For example:
†˜Let me do the talking,’ Helene answered. †˜Like I said, I’d like to be very much alive when I leave this place. We can’t risk you unintentionally insulting them.’
†˜I’m not going to insult them. I’ll be a true lady, I promise.’
†˜We both know that that’s not what’s going to happen. Besides, you said it yourself. That there were no ladies in the arena.’
Here I felt like I already got the point. I get the dynamic between these characters and having it just described to me again was kind of annoying. All you need out of that is:
'Let me do the talking,' Helene answered.
'I'll be a true lady, I promise.'
'You said it yourself, there are no ladies in the arena.'
In my opinion that would get the same points across without the exposition which you have already given to us earlier in the story. Myrina is a loud mouthed, fiesty character that's gonna get them into trouble and Helene just wants to do the job and get out.
2) Descriptions like "The red head rolled her eyes." I find a little odd because it makes me feel so separate from the main characters. It depends how you want the reader to feel, but for me it seems too judgemental to describe the characters by hair when I should probably be on their side and feel their experience. It seems like something you'd say about someone you felt distinct from, someone you didn't know. If you were in a group of friends, one of which was a red head, would you refer to her as such? It would seem like an odd thing I think.
But again, it depends how you want people to feel. If you want to tell a story in a very objectifying way where the reader feels like they're watching the events on the sidelines then it could work. You could in fact rework some of the descriptions to make it feel more like you are a spectator at the colosseum and that could be quite effective but it would need to be made more clear.
3) The sex could be a little more descriptive in terms of highlighting titilating qualities in the action. So rather than just saying 'this happened, then this happened, then this happened' or even rather than only being abstract about it and saying they feel ecstasy (which is still good stuff), you could try adding stuff like... "Their nipples become erect as their flesh is squeezed between each binding of the tentacles." If that makes sense. Just something that gives me all those juicy details, as well as filling in their emotional states.
But hey, I don't know much about this really. It's just about going with your feelings. Hopefully I don't sound too critical as I usually come across that way. Keep it up and we can only get better!