>>2757745works alright with the mirko and shantae embeds for me, I don't have Lum so I can't test her. I don't know what checkpoints your using but it works best for me with 7th layer / AoM2
You might also have a bad prompt embedding or a generic positive/negative prompt word that's messing it up, you can try increasing the emphasis of love letter also.
playing with it more it's probably a tad undercooked, I made it in the span of ~4 hours and didn't properly test it because I wanted to get it out today and was unsure If I'd have the time/drive to continue finetuning it later in the day, I can upload the dataset somewhere if someone wants to take a crack at improving it