[Tool✓] Which tools for expanding+inserting new gen?

Hi all, i tried a few days ago different tools like Pge / GH3 tools etc, but with pge after i clicked on expanding i thought it worked but then when i tried using advanced series sprite Tool to insert 18 new pokemon i get each time the error " Lzz7" something like that, and when i try using Gh3 tool expanding i see in list down of the added " Bad egg" and others " Temp"

My priority is expanding pokedex so that i can add new pokemons to Rival team

(FIRE RED USED CAUSE I LIKE THE GRAPHICS A LITTLE BETTER THAN EMERALD)

( i heard of rom bases / patches but i don't want to use those for now)

Which tools or instructions would you reccommend ?

( writing from phone)

Why don't you insert the new Pokémon using PGE? You can do that, and the expand 'mon function works too. In the "Pokémon Editor" window you can insert almost everything that you will need in order to add new Pokémon. A-Series tools won't work anymore, the expand method changes a lot of pointers in your rom.

Ah, good good, thank you @Hijikata t