Dig, Lazarus, Dig! (слэш)

Sequel to The Firstborn is Dead
The Multiverse: The hypothetical group of multiple universes that exist parallel to each other, comprising everything that exists in space, time, matter, energy, and the physical laws and constants that describe them. Some are very different, but some are so similar, they may as well be mirror images.
In the last installment, our heroes managed to rescue Yagi Toshinori's parallel counterpart from his horrifying circumstances, but at an incalculable cost. As the counterattack from his captor draws ever closer, our heroes must find a way to keep this precious, frightened civilian safe no matter what. They'll soon discover this is easier said than done, because not to be outdone, the villains of their own world are about to put their own plans into action...