Hi @Cyanirl
Glad to see the issue has been solved.
As a side note, you can rechallenge Horon after 3 days to get a Rapidash mount, and challenge him again after 3 days to replay the Dark Realm quest just for fun.
I hope that info will be of use to you.
I'll be locking this thread now, if you run into any further issues, please do make another one.
Thanks and have a lovely day!