Trouble beating elite 4

Hey guys I’m having trouble beating the Elite 4, one day I actually did I didn’t know if have to battle Cynthia and I failed. Now I’m back to struggling to get past the last member, I don’t know who to use at this point. This is my current crew, any tips or tricks or changes I should do?

Hey guys I’m having trouble beating the Elite 4, one day I actually did I didn’t know if have to battle Cynthia and I failed. Now I’m back to struggling to get past the last member, I don’t know who to use at this point. This is my current crew, any tips or tricks or changes I should do?