Sorry for the slightly delayed answer! 

About Sascha, yes I think we will see them again for two reasons:

• the camera: I don’t know if it’s a death scythe or not, but it’s so out of place compared to what the Shinigamis usually bring around when they work that it automatically makes them stand out.

• the “Shinigami vocation”: there again, between UT who deserted and others like Will or Rudgar who just don’t like their jobs (for obvious reasons, since it’s more of a punishment than anything else), Sascha stands out by “having much more fun than when I was alive and a human”.

They look and sound younger than any other Shinigamis to me since we’re on the subject, so I wouldn’t be surprised if they became a Shinigami “recently” (knowing the recently could mean a century for what we know lol).

I have no real idea whether they’re a She or a He to be honest, could be either, even though we know that the majority of Shinigamis introduced so far (so the ones sent to collect the souls) are male (I know Grell sees themselves as a woman of course, but I’m thinking they might be considered as male by the Shinigami hierarchy when it comes to this job). 

Anyway, I believe Sascha standing out the moment they were introduced means that Yana has something precise in mind when it comes to their role in the plot, but what exactly, I think it might be too soon to tell. 

The only thoughts I’m having on the subject would be that Sascha could prove to be intrinsically linked to the sub-plot of the early WWI seemingly starting, since they apparently found that idea so very interesting in ch105:

So don’t worry about Sascha’s character, they will definitely come back (when is the question now). 🙂

Hope it answers your question, and enjoy the rest of your sunday!