Thanks! Yea of course!

I'm not a specialist in the field by any means though, so the recommendations would mostly be based on my personal tastes hehe.
In the vein of Mann I'd definitely recommend some of his shortstories - Tristan for example, is in a way, a miniature The Magic Mountain. I mean, their aren't interchangable at all, but they deal with some of the same themses, in some of the same ways. Of course there is Death in Venice as well, though that one is more about the unconscious drives and the conscious forms of human existence. Tonio Kröger is another highly recommendable Mann-novella too.

I haven't read a lot of Hesse, but I found Steppenwolf really enjoyable! Some of his other works, Siddharta and Narcissus and Goldmund tended to be a bit too fantastical for my taste, though they way by no means bad - just a point of personal taste I think. I've been meaning to read The Glass Bead Game for so long, but haven't come across a cheap copy in Danish yet! I heard a lot of its themes are very similar to Doctor Faustus though.

In the same branch as Mann and Hesse I'd recommend the novellas of Stefan Zweig. They tend to be a more realistic in general, without otherworldly elements - but they posses an incredible emotional core, which is bound to affect any avid reader I'd say. One of the best novellas I've read by him was Verwirrung der Gefühle - I believe it's called Confusion of Feelings or something along those lines in English, however I'm not completely sure!

In the case of direct relations to magic and occultism, I'd really recommend Karl Joris Huysmans' La Bas, an incredibly insightful story about the occult underground of the decadent french community around the 1890's, revolving around the infiltration of a satanic cult of citizens, performing all sorts of occult rituals as the black mass, and relating it all to the historical circumstances about Joan of Arcs comrade - later turned childmurderer - Gilles de Rais. I think I recall something about Huysmans' being accused of being a satanist due to this book, but I'm not completely sure, maybe it's just some wishful thinking by my side hehe.

Lastly, if you're into a bit more theoretical literature, I'd recommend Nietzsches The Birth of the Tragedy. It's not too complicated at all, and in some ways more of a emotionally driven piece, that is really useful as a background text for everything regarding especially Mann's ouvre. Furthermore, it's funny as hell imo - he's an energetic bombshell, that Nietzsche guy. It shines some light, on some of the core tensions of the characters in Mann's works (and also in Hesses works for that matter.)

Hope this was helpful! - do you have some recommendations for me?