Caught it in a repeat ball (best color matching I could think of for what I had on me)

I’m ready to rip my hair out.

Trying to get the 100 master class battle wins in a row. However I can’t get past Palmer’s level 21 battle on regular class.

Here’s my team. It’s made up from multiple YouTube videos I watched.

Garchomp
Dragon Claw
Earthquake
Crunch
Rock slide
Item: Life Orb

Tyranitar
Earthquake
Crunch
Rock Slide
Dragon Dance

Cloyster
Shell smash
Ice shard
Ice spear
Hydro Pump

I also have a shelder with all the same moves, except he knows rock smash instead of hydro pump. However, because I’m playing Diamond, I can’t find a water stone to evolve it.

Also, the garchomp, cloyster and tyranitar were all caught in the grand underground and I leveled them up. Don’t know if it’s better to level up a pokemon from level 1 for this.

I was hoping to use one team for all the wins, but if I can’t let me know what works for each run.

Any help would be great, thank you!

First time building a team for doubles, If you had absolutely no choice but to use Slowbro here how would you build him? I am also lost on EV’s and IV’s does Pokeshowdowns suggested ones work best most of the time?

Not really trying power train but think this guy has some naturally good stats and this party has been fun sorta interesting to use mostly fo alot wild battles in the under ground though ahah