Subaru Natsuki had been forgotten about and tortured by his so-called allies, causing him to finally give up on life as a whole. Just as he's contemplating his next move, a cosmic evil by the name of Nekron appears and offers him a deal: die one final time, become his herald, and extinguish all life in the world...in exchange for a permanent sense of peace and calm.

Just as his adventure is almost over, Subaru Natsuki and the 7 Witches are introduced to a mysterious figure that wants to understand how cause and effect apply in their "verse". But just where does this mysterious Dr. Osterman come from, and what type of experiment is he planning?

Natsuki Subaru had finally found his way back to sanity through the unfortunate murder of Rem. But just as he was about to lament his own powerlessness and die in vain yet again, a demon the likes of which the world has never seen finds him and forces him into a one-sided partnership. Now the unwilling host of the vile Eclipso, he can only watch as the non-angel wreaks havoc on all

A crossover in which the events of Ben 10 and Re:Zero connect, with Kenichi joining Subaru that night he went to the convenience store. While walking back, something happens, but it isn't related to the Witch. Instead, a pod appears out of now where, containing a watch.