25 of a specific one and you are right
Edit: You are gonna fight against 6 npc with 4 pokemon lvl 75 each
You're welcome ;)
About the moveset, mostly use: Sludge bomb [stab, %Poison], Giga drain [stab, Sustain], Toxic, Sleep powder/Synthesis/Leech Seed.
Here's how to get the ones you dont learn via lvl up: https://pokemonrevolution.net/forum/viewtopic.php?f=120&t=29668
Item to hold?: Black Sludge to recover hp
Good luck and see you!