This was a test LoRA trying to replicate the ultrakill like style of a solid colored character with a neon like background, i've tested with blue background and red background.
Recommended strength is at least 1.5 to 2.0
If you want to see the character with not a solid color you can try with 1.0 of strength.
You may want to generate similar artwork to get a more neon like style, i did it on the cover artwork 2 times, one time for HighRes and another time to fix the hands, both at 0.8
I've also used my Limited spot color LoRA with strength of 1, its a good combo as this LoRA was also trained with a similar style images, you just need to erase the "Black Background" from the trigger word and its good to go
LoRA: https://pixai.art/model/1848280398685776630