Nine Moons in a River of Stars, Phase Six by Xen

Reunited, Sho and Naoki must face their feelings – yet fear stands in their way. Fear of what the strange new changes to Sho’s body mean; fear that if Naoki doesn’t escape before he, too, begins to change…
…he may be trapped in Marrow forever.
Yet Naoki’s loyalty will not waver.
And even while Sho pleads with him to run, the magnetism between them draws them closer together. Explodes. And when Sho’s greedy, monstrous love claims Naoki…
Not even fear can stop years of pent-up desire unfolding between them.