These three were mostly ripped from Nico Nico Douga (NND), except for the first song in Denjin Makai (ripped using BridgeM1):

Denjin Makai
Ghost Chaser Densei
Denjin Makai II / Guardians

Denjin Makai OST Trilogy - Download - 4shared (http://www.4shared.com/zip/Jv7JMJGd/Denjin_Makai_OST_Trilogy.html)