@ScorelessPine
Coming solely from regular ORAS experience I would say rebattling trainers is your best bet. Sad to say, except for the facility in Mauville Hoenn has no redtaurants like Kalos.
That said, a (temporary) revision of your pokemon wouldn't hurt either. As it is you have 2 pokemon weak to fighting type which are essentially automatically potion fodder.
Lets touch on each pokemon separately.
shedinja - While admittedly at first sight one would say wonder guard ghost is perfect for fighting type, the ORAS AI is very keen to switch to a pokemon that can take it out one way or another. This fact is something to take to mind and thus scouting out brawly's move sets through soft resetting (game one, not homebrew. LRStart) can be used really well.
Eevee - learns Charm as fairy move on lvl 29 so lvl 30 can be Sylveon.
Aaand i'll continue this by editing in an hour or so. Typing this much from mobile is annoying :rofl: