Wanted to see what Madmark Style would look like in Illustrious and here is the result so far.

If you don't want the style to interfere with how it generates your character much I strongly suggest turning the strength to something around 0.6 to 0.8 to still get a good mixture of style and character.

ALSO, I strongly recommend using WAI-NSFW-illustrious SDXL or Hassaku XL as I've found the base model of Illustrious XL has issues keeping characters skin color consistent especially if the strength of the lora is above 0.8. You can still use Illustrious XL but not highly not recommended if using with strengths above 0.8. You can find the following checkpoints below in the Suggested Resources section.

Main Trigger Word: madmark01

Other Trigger Words for more effectiveness: sweat, shiny, shiny skin, oily, oily skin,

Also, I have just a few characters trained into it. Some may do better than others and some may not but I haven't tried some of them yet as of posting. You'll have to test and see though by using the following Trigger Words below for them. I don't think they're perfect though and they may not work perfectly either:

Summer Smith from Rick and Morty: summersmithmm, hair bun, orange hair, pants, tank top

Morty Smith from Rick and Morty: mortysmithmm, yellow shirt, pants, brown hair

Undyne from Deltarune: undynedeltarunemm, police uniform, police, blue skin, colored skin, yellow sclera, colored sclera, head fins, hat, policewoman, uniform, sharp teeth

Ragatha from The Amazing Digital Circus: ragathaMM, dreadlocks, puffy sleeves, doll girl, button eye, red triangle nose, bow, hair bow, blue dress, purple dress

Millie from Helluva Boss (Only used 1 ref to train for her so don't expect much) : milliehbMM, red skin, colored sclera, colored skin, mole, mole under eye, demon girl

Marceline from Adventure Time (Only used 2 refs to train her so don't expect much): marcelineATmm, black hair, fang, low twintails, twintails

Connie Maheswaran from Steven Universe: conniemaheswaranSUmm, dark-skinned female, dark skin, brown skin, earrings

I'll get to sharing the others later though.