Since this is an RP you need to know how to battle.
For Trainer Battles, Gym Leader Battles, & all other Story-Related Battles will be done using Pokemon Showdown to get the most accurate results, but for Wild Pokemon Encounters you must Roleplay Battle.
These battles will be done on the page of the location your character is currently in, using the comments section. A Trainer shall post in the comments to let an admin know they want to travel in the area and trigger an encounter.
The admin will then take control of the wild pokemon and the trainer shall battle it.
Here is an Example of how the battle may take place.
Grabbing one of the Pokeballs on his belt, Doku walked into the grass. "Alright, Pokemon, time to come out and get caught!" he declared as he began to search around.
Without noticing it Doku gets caught off guard by a Shiny Mewtwo that jumps out of nowhere. (Level 67)
Without skipping a beat, Doku grabbed a Pokeball off of his belt and sent his Pokemon out into battle. "Drapion! Going forth!" he called out as his mighty Ogre Scorpion jumped out of its ball with a shout. "Your move, freaky deaky Mr. Sneaky!"
The Wild Mewtwo stands there and with the power of his mind creates blades and hurls them towards Doku's Drapion, although the move has no effect on it.
"Psychic attacks, eh? Drapion! It's showtime! Hit 'im with your Crunch!" Doku commanded. In response, Drapion jumped at Mewtwo, mouth agape, in order to munch on its head.
The attack is very effective, leaving the wild Mewtwo weaken. The wild Mewtwo once again tries to use Psychic Cut.