Things to try
Guitars: They sound quite honky/mid heavy, try scooping them a bit (especially rhythm guitars).
Lead guitar: Stereo delay and reverb, you need to make it sound bigger.
Rhythm guitars: Very undergained!
Clean guitars: Add delay and reverb.
Drums: Painfully obvious they're programmed. Download this mixpack and study the drum mid
http://www.ultimatemetal.com/forum/...-8-minute-prog-deathcore-mixing-practice.html John has put a lot of love in to the programming.
The drums are so thin, try make them bigger. I like using the room mics for this and reverb. Parallel compression helps a bit too.
