Step 1: Enable the code titled "Encounter Mod On (v1.0.1)"
Step 2: Choose any of the following codes you want (You will need to edit your cheat file to customize these codes):
[Encounter Pokemon (v1.0.1)]
08000000 03075530 0000000W 0000XXXX
First off, go to this post for a list of IDs:
https://gbatemp.net/threads/pokemon-scarlet-violet-cheat-database.621563/post-9993003
Then, replace XXXX with the column that says "HEX".
Finally, W is the form ID. For most pokemon, this will be 0. For Hisuian Pokemon, it is 1.
[Encounter Item (v1.0.1)]
04000000 03075538 0000YYYY
First off, go to this post for a list of IDs:
https://gbatemp.net/threads/pokemon-legends-arceus-cheat-database.606215/page-24#post-9725329
Then, replace YYYY with the column that says "HEX". Finally, encounter the Pokemon in the wild and catch it. When you catch the Pokemon, it will be holding the item you chose. Also, Master Ball is 0001 for YYYY.
[Encounter Level (v1.0.1)]
04000000 0307553C 000000ZZ
First off, think of a level from 1-100 that you want the Pokemon's level to be. Then convert that number (decimal) to hexadecimal. You can use an online calculator to get the proper value.
EXs: Level 1 = 01, Level 99 = 63, Level 100 = 64.
Step 3: Go inside a building. Then walk outside into the wild. All Wild Pokemon that spawn will now have the characteristics you set for them.