Special needs brother needs help, E4 battles

Hello,
My little brother (who’s 16 now, but developmentally about 8) can’t beat the elite four. As far as I can figure out, apparently the game is locked behind defeating the elite four, and he can’t do it. Normally I would just complete it for him, but its finals week, plus I’ve got a full-time job now. The nearest I can figure is me trying to remaster the mechanics for the gimmicks each member uses, but I really don’t want to. I’m tired after work and I’m too frustrated to do it as well. I tried, even got past two of them using his team members, but usually get knocked down by the hippodon as part of Dirtman’s team.

Is there any way I can skip this for my brother? He’s gotten to the point where he’s tried breaking the computer, which is not great for obvious reasons. The game is obviously wonderful, he already beat all the original Pokemon games and he’s been obsessed with this one for nearly 6 months, which is pretty long for him. I’m glad he’s found something he can enjoy, and I don’t want it tarnished by his own frustration. I’m honestly impressed he’s handled it thus far, because according to my mom, he’s held out for nearly two weeks before having a meltdown. I just need some way to bypass this or beat it quickly so my brother can continue another quest, because he really wants to see Meloetta.

Any aid appreciated. I’ll try and stay on top of this thread throughout the weekend, but no promises as finals are next week. Thank you all so much in advance.

I TAKE IT BACK I BEAT THEIR LITTLE BUTTS THANK GOD. spent a ton of money, but the real saver was using tms in between battles. now im gonna play minecraft, too much adrenaline in me