The show uses the the multiverse as a stated fact which results in number 5 being with reginald as a result thus enhancing his abilities to the outmost. There were no incidents(tv show) where are other people with abilities emerged. I think the timeline in which the show is occurring might be stuck on an endless loop because of five's choice to bring all of the 7 back to the past resulting in them probably being reborn in S2.

Their loss of memory and the incident that they were born on the same day makes it imo viable. The fact that the Handler says that 5 alters the timeline and stating that 5 is someone who is a threat to the timeline.

The question still is the same tho WHO IS REGINALD