Just curious

is there any mega stone to be found in dragon ruins at any point in the game? if so what is it and how do i get it?

Delta Metagrossite (Ruin)

how do i get it?

How far are you in the game? I picked it up when I fought Taen for the second time

You’ll need Hiking Boots

hmm. just won against taen in dragon ruins for the first time, when he tries to make the legendary “Namehere”

The Hiking Boots are only obtained just after the elite 4 so you’ll have to wait a little while