You have to beat the second gym, and get the CUT item from the Cutter's house. After that go back into the forest and find the two small trees, use CUT on them and follow the path behind them to the end. You will find her pendant there. Bit of advice though, bringing a good ground type if you can, or a lot of high LV pokemon. You may need it.
Abyssal The Watcher
Recent community posts
I've been trying to find the new secret event in the library, and I have found three things that I don't think are ment to happen on 0.70a.
1. You can glitch you way into the library in both evening and night by going to either the reception or the book room during the afternoon and using the wait option
2. Though it's midnight, Cleo will still appear in the reception and you can interact with her, though it will only be the usual spend time thing. {If this or the next thing I found is the secret I will be highly disappointed}
And 3. Cleo will appear in the library even on Sunday {which if I remember correctly is the day she takes her break} from morning to noon.
So, in conclusion, those are either bugs and the "Secret Event" is a load of horse manure, or one of those is the secret event. Good day.