Therefore I made a video to demonstrate how to get it
The language is cantonese but included English sub-title.
1. talk to subway manager
2. talk to yorkie
3. find Yorkie’s Brother (random location at A~E below)
A: small island in route 21 (see video @ 1:27)
B: victory road
(Captured by Zallyboi)
C: saffron poké Mart
(Captured by Atem)
D: power plant
(Captured by samxwbos)
E: diglett’s cave
(Captured by detamon)
4. give him 50k and back to Yorkie
5. get nocturnal feather from wild Pidgeotto (at Morning/Night only)
6. give it to yorkie for HM 02 fly
7. find subway manager for reopen the subway.
For step 3:
Thank you all of you providing screenshots it help a lot!!
For step 5:
Use Pokémon with “compound eyes” at 1st place
(Raises accuracy by 30% and increases the probability of wild Pokémon holding items.):
Two way to get feather:
a. Use pokemon with Super Fang (e.g. Ratatta)/ False Swipe (e.g. Scyther) to consume it hp (prevent killing) and catch it.
(I like this one because i need Pidgeot for my team so i can choose the best iv Pidgeotto)
b. Use pokemon with Covet (e.g. Mankey) to steal items directly.
(Save time and pokeballs)
"Theif" and "frisk" (to see if holding items) now is work too!
HM02 Fly CANNOT USE OUTSIDE BATTLE!
that means you cannot fly to another cities directly!
so do it only if you really need the powerful moves for your bird and the subway service.
this mission really cost time and money...