Route 758 will lead you to Route 757 which connects to Holdharbor. Not only is it foggy but iit's like Route 757 and has savanna like grass so watch your step because there are some old tumbstones laying about there as well. You don't need a broken ankle after all. Here we have the typical creepy Pokemon that haunt the area ranging from Ghastly, Sabkeye, Duskull, Shedninja, Absol, Houndhour, Vulpix, Baltoy, and Drifloon. If you want a well balanced team, one of these are great to have.
Good luck, Pokemon Trainers.
Pokemon:
Gastly
Sableye
Duskull
Shedinja
Absol
Houndhour
Vulpix
Baltoy
Drifloon