There is the difference in the Snare, obviously. For some reason the Snare sound in DeathsBell doesn't seem to fit comfortably. Chimera also has a deeper/thicker guitar line, which seemed, in my opinion to be a couple DB too loud. Maybe the biggest difference is the Snare and actual guitar part between the songs. I can't hear much of the Bass.
What if you doubled (or tripled) the guitar in Deathsbell?