I read this arc all over to remember what happened and the pace was fast.
Imo it was supposed to be a kind a small arc to introduce the new layer and get some more comrades (Faputa) because I don't think will be able to carry the group all by himself from now. Sadly Reg is weak, he has an OP body but his mind can't follow so he get rekt every time.
So well, the point of this arc was to recruit Fatuta but it took the author around 4 years to publish it instead of 1 year or 2.