It's a manga in which 2 boys shared what the other lacked>mana and life force but one betrayed the other and cursed him to be banished in another dimension for a certain number of year before being released for one day.
It might be HandxRed,read it a long time ago (sad it died so young), completely translated by iskultrip scans. The summary from baka-updates: "Jim is a young boy bound by a curse which seals him in the darkness of purgatory for 100 years. Bound by a curse, half of his heart is held by his best friend Luca. Due to Luca's betrayal, Jim lost both his 'best friend' and his 'heart'. Once every 100 years, Jim is allowed to roam free for only 10 days and search for Luca whom he must defeat! Hatred replaces friendship and friends become enemies, now, who will be the one left alive? Note: This series has a total of 24 chapters. Volume 3 ends with chapter 19 and an extra. The remaining chapters were never released in bound format." edit: just checked, it looks like only the bound chapters got translated, so it ends at chapter 19,, you can download all 3 volumes from the scanlator's website.