So, i’m just doing a first playthrough in the game and i get to the elite four, I have never struggled so bad on these fights in my life, its so bad to the point that I just grinded the rest of these pokemon to lv120 to try and beat them and still cant, any help? this is my team to just a look at what i could change; mew, d. charizard lv120, d. aggron, d. typhlosion, giratina, and tyranitar w/ armor. (the delta aggron and typhlosion are from trades)
I have found that changing tm’s before going to different fights is a gamechanger. Grind a bit at the Sonata tracks to get some cash before getting revival herbs at the Trainer’s market. Additionally, pull up the pokemon weakness and strength charts. The hardest one for me was the Baton Pass battle, and surprisingly, giving your first pokemon a Chesto berry to hold is a game changer for taking out the stupid Smeragle that insists on putting you to sleep. Every turn counts in that battle, and using Destiny Knot and Perish Song was super helpful, as Destiny Knot could be used to take out pokemon that hit during the turn, and Perish Song forced the AI (on easy mode) to give up Baton Pass and use manual switch instead. Infestation can also be helpful, or any trap move.
For the other pokemon trainers, the only one that gave me more than average trouble was Dirtman as I unaffectionately call him, and surprisingly, a bug type move helped a ton. Additionally, having a higher speed stat then the other pokemon was needed, and Destiny Knot saved my butt when it was something I didn’t have a supereffective move on.
Good luck! I had a ton of problems with this as well, but I cleared it for my brother after a couple dozen tries. Soft reset will be your friend.