Hello guys! So I downloaded this game and completed the story and league last year. Now I started playing it again and want to complete the pokédex and get the shiny charm. For getting it, do I have to catch all delta Pokemon too? Or do I need to catch all regular Pokemon only(upto Zygarde)? Thanks in advance.
Yes, you need to complete the pokedex and get all 921 mons. This includes all of the delta mons, but does not include entry 925 (it’s a secret mon that you can get after dex completion, so don’t look it up if you don’t want spoilers 
) nor the non-existent entries 723-6 (there just aren’t any entries for these numbers). Happy hunting :)) !
P.S. Theres a page on the wiki with the locations of all the mons, in case you get stuck 
Oof that’s gonna be a tough grind, but I’m down! Thanks for the reply!
No problem, glad I could help :)). Good luck on the grind! If you need help with some of the harder to get deltas, you can always ask in the trade section here or on the discord and someone will probably be able to you out.
Sure!