Part 9: Beat Marlon — Humilau City Gym, badge 8

Beat Marlon — Humilau City Gym, badge 8 opens 6 areas.

Where to go

1. Victory Road

   Wild: Boldore 100% · Lv 47-50, Excadrill 100% · Lv 47-50, Audino 95% · Lv 47-50, Druddigon 80% · Lv 47-50 +26 more

2. Giant Chasm

   Wild: Excadrill 100% · Lv 44-47, Audino 85% · Lv 44-47, Basculin 70% · Lv 35-50, Poliwag 60% · Lv 40-70 +21 more

3. Seaside Cave

   Wild: Excadrill 100% · Lv 34-37, Frillish 70% · Lv 25-40, Luvdisc 60% · Lv 40-70, Seel 60% · Lv 25-40 +11 more

4. Route 22

   Wild: Audino 85% · Lv 39-42, Basculin 70% · Lv 15-40, Goldeen 60% · Lv 40-70, Marill 60% · Lv 15-40 +11 more

5. Route 23

   Wild: Audino 80% · Lv 48-51, Basculin 70% · Lv 40-55, Buizel 60% · Lv 40-55, Poliwag 60% · Lv 40-70 +19 more

6. Route 21

   Wild: Frillish 65% · Lv 30-45, Jellicent 60% · Lv 30-45, Luvdisc 60% · Lv 40-70, Remoraid 55% · Lv 40-70 +4 more

Everything you can have caught by this checkpoint · Open the interactive guide

It also doesn't say when 5 of its areas open up, so they are listed together in the last part rather than guessed into the story.