I think kalos/gen 6 would be 2 month because it only have 6 legendary and alola/gen 7 would be 4 -5 month because have 25 legendary/ultra beasts
the ultra beasts is it gonna be its own chapter
Actaully i thought like he also gotta do the side chapter pretty long too because of that i also count
Gen 7 will probably be broken into a few parts, 1 for subs/mythicals, 1 for the main legends, 1 for Ultras in their own side chapter
I said recommed each month each 5 pokemon legendary/ultra beast