Loveless Vol 10

Loveless Vol 10 by Yun Kouga. A Yaoi/BL manga rated Older Teen, published in English by Viz Media.

Twelve-year-old Ritsuka Aoyagi is still reeling from the murder of his older brother when a stranger named Soubi appears, claiming to have been his brother's friend. Soubi pulls Ritsuka into a world of mysterious spell battles fought in pairs, and toward the truth behind his brother's death.