I want a theme to Rek'Sai that is NOT the original Login theme. Literally that is the only thing the internet ever gives me when i put Rek'Sai and anything related to music. I need something different and more dramatic and extended. Preferable no lyrics (cuz she can't speak, and it'd make playing harded)
I'll try and come up with something for you :)
I assume you just kinda want something to play in the background as you play Rek'Sai?
I think the Command and Conquer: Tiberian Sun soundtrack has a very nice corrupted, Void-like feel.
Not all of the songs fit quite as nicely to Rek'Sai in my opinion, but just off the top of my head I think the original menu theme, Dusk Hour, Approach, Gloom, Ion Storm, Time Bomb, What Lurks (appropriate song name for Rek'Sai ^^), and the Firestorm expansion Menu theme fit this pretty well. They're not particularly energetic or epic pieces at most times, but they do fit the vibe I kind of get from the Void. There's probably other songs in this that you may like better, so my advice would be to find those individual songs and put them in a playlist.
Hope I have helped!
