Title: 666 Satan
Genre: Action, Adventure, Comedy, Drama, Fantasy, Shounen, Supernatural.
Volumes: 19
Status: Completed

Plot summary:

In the not too distant future, mankind battles over O-Parts, relics from an ancient civilization. It takes a special kind of person to unlock the full potential of these remnants from the past, and a unique breed of humans known as O.P.T.s (or O-Parts Tacticians) become a force to be reckoned with. Unfortunately, O-Parts can be used for good or evil purposes.
Jio is a young boy with a tragic past who only trusts one thing in the world: money. Little does he suspect that he is actually a very powerful O.P.T., and inside him sleeps a demon of incredible ferocity. He meets up with a girl named Ruby, and together they decide to embark on a dangerous quest to discover as many O-Parts as they can. Will Jio help Ruby realize her dream of becoming a world famous treasure hunter? More importantly, will Ruby help Jio realize his dream of–world domination?!

Taken From Baka-Updates

Download from Megaupload.com:
Language: English
Volumes: 18
File size: +/- 33MB
Status: Not Completed
Scanlator: TMI Scans

Volume 01
Volume 02
Volume 03
Volume 04
Volume 05
Volume 06
Volume 07
Volume 08
Volume 09
Volume 10
Volume 11
Volume 12
Volume 13
Volume 14
Volume 15
Volume 16
Volume 17
Volume 18