Yeah, Dead Congregation is definitely Satanic.
Here are some other bands you might like:
http://www.myspace.com/theoceancollective
http://www.myspace.com/miserysignals
http://www.myspace.com/theesoteric
http://www.myspace.com/theendmusic
http://www.myspace.com/neaera (will be touring Germany with As I Lay Dying this March and April)
http://www.myspace.com/swedenevocation
http://www.myspace.com/blackdahliamurder
http://myspace.com/obsidianrocks
http://www.myspace.com/meshuggah
http://www.myspace.com/fredrikthordendalsspecialdefects
http://www.myspace.com/coprofago
http://www.myspace.com/tesseract
http://www.myspace.com/scarve1
http://www.myspace.com/textures
http://www.myspace.com/inquest1
http://www.myspace.com/abortedmetal
http://www.myspace.com/despisedicon
http://www.myspace.com/animosity
http://www.myspace.com/iondissonance
http://www.myspace.com/psyopus
http://www.myspace.com/intothemoat
As for technical death metal, these ones are great:
http://www.myspace.com/pavor (listen to Perplexer Perdition Projectile and Wroth Volcanic Vent)
http://www.myspace.com/augury
http://www.myspace.com/blottedscience (more progressive metal, but is a lot heavier than most, and sometimes ventures into death metal territory; supergroup with Ron Jarzombek-guitars [Spastic Ink, Gordian Knot, Watchtower], Alex Webster-bass [Cannibal Corpse, Hate Eternal], Charlie Zeleny-drums [Behold...The Arctopus, Jordan Rudess])
http://www.myspace.com/cosyns (solo project, instrumental progressive/death metal)
http://www.myspace.com/sepiadreamer (instrumental progressive/death metal)
http://www.myspace.com/psycroptic
http://www.myspace.com/defeatedsanity
http://www.myspace.com/wormed
http://www.myspace.com/sleepterror (instrumental death metal/jazz)
http://psychotogen.com/
http://www.myspace.com/disavoweddm
http://www.myspace.com/decrepitbirth
http://www.myspace.com/pitn (Pitbulls in the Nursery)
http://www.myspace.com/goryblister
http://www.myspace.com/illogicist666
http://www.myspace.com/odiousmortem
http://www.myspace.com/gorod
http://www.myspace.com/spawnofpossession
http://www.myspace.com/atheretic
http://www.myspace.com/cenotaph
http://www.myspace.com/elementaeonspast
http://www.myspace.com/sickeninghorror
http://www.myspace.com/hacksawtothethroat
http://www.myspace.com/fractalpoint
http://www.myspace.com/insidiousdecrepancy
http://www.myspace.com/neglectedfields
http://www.myspace.com/theoryinpracticeband
http://www.myspace.com/neuraxis
http://www.myspace.com/demilich
http://www.myspace.com/129690095 (Liers in Wait)
http://www.myspace.com/fwth (Gorguts)
http://www.myspace.com/sulaco
http://www.myspace.com/kalibas
http://www.myspace.com/deathmetaldomination (Dominion)
http://www.myspace.com/mephistophelestas (Mephistopheles)
http://www.myspace.com/theserpentinquisitor (Stargazer)