This enemy, along with Fallen, Flesh Reaper, and Soul, can be encountered in the present if they are not killed in the past. You can fight them again in the past even after killing them in the present. But, they cannot be encounter vice versa.
Note: If a Soul is with a Fallen, the Soul will posses the Fallen and merge to become a Fallen + Soul. It is possible to never encounter this enemy if a Soul dies before it is able to posses a Fallen.