If you want just normal Gardevoir do the following and make changes as needed. See note at the bottom if you want a very pokemon style

Default Gardevoir:
gardevoir, white dress, creatures \(company\), game freak, nintendo, pokemon, pokemon \(game\), bangs, colored skin, female focus, flat chest, gen 3 pokemon, green hair, green skin, hair over one eye, multicolored skin, pokemon \(creature\), red eyes, short hair, two-tone skin, white skin

hair styles (Do not use with the Default Gardevoir Prompt just the 'gardevoir' tag):
side ponytail
ponytail
twintails
long hair
hair bun
any hair color

artists (Use at the end of the Default Gardevoir Prompt):
(kionant:0.8)
(drunkoak:0.8)/(drunkoak:0.9)
fir3born (couldn't decide a best weight), flat chest, nsfw

concepts (Use at the end of the Default Gardevoir Prompt unless stated otherwise):
mega gardevoir
(dr.voir:1.2), blue hair, glasses, labcoat, black panties (don't use default just 'gardevoir' alternatively see below)
clothes of any kind (maid works well)
pokemon unite outfit (see below for prompt)
mecha
swap 1girl to 1boy and add penis to get male gardevoir (don't use this with the default prompt)

Shiny Mega Gardevoir:
gardevoir, creatures \(company\), game freak, nintendo, pokemon, pokemon \(game\), bangs, colored skin, female focus, gen 3 pokemon, blue hair, blue skin, hair over one eye, multicolored skin, pokemon \(creature\), orange eyes, short hair, two-tone skin, white skin, black dress, mega gardevoir

Full Dr.Voir Prompt:
dr.voir, gardevoir, creatures (company), game freak, nintendo, pokemon, alternate color, bangs, blue hair, blue skin, breasts, choker, collar, collared shirt, colored skin, glasses, hair between eyes, hair ornament, hairclip, labcoat, large breasts, mole, mole under eye, multicolored skin, open clothes, open shirt, pokemon \(creature\), red-framed eyewear, red eyes, semi-rimless eyewear, shiny pokemon, shiny skin, shirt, short hair, short sleeves, tareme, two-tone skin, white shirt, white skin

Pokemon Unite Outfit:
gardevoir, gardevoir \(fashionable\), creatures \(company\), game freak, nintendo, pokemon, pokemon \(game\), pokemon unite, bangs, bob cut, bonnet, capelet, clothed pokemon, colored skin, female focus, flat chest, flower, gen 3 pokemon, green hair, green skin, hair over one eye, hat, hat flower, multicolored skin, official alternate costume, one eye covered, pink trim, pokemon \(creature\), red eyes, red flower, short hair, two-tone skin, white capelet, white headwear, white skin

As always:
Trained on Anything v3
Demos are Anything v4.5 with 0.8 weight LoRA

Note:
I ran out of room for included images but using the default prompt along with the Harada Takehito LoRA I released (and putting harada takehito at the end of the prompt) does a surprisingly good job of emulating the correct style about 80% of the time.