Reeve

Reeve was a member of the Death March Division who takes part in the [battle ON Nomalis before human forces there are quashed?] Reeve also dealt with shapeshifting rats in some way.

2024 Halloween Special

Reeve is seen alive after his implied death,

Reeve tries to stab Emile, then relents

Reeve also explains he was reached out to by a "teacher;" this could refer to either Tamnayal or Kallisto [but it is suspected he meant Tamnayal].