hmmm, rtrn soulmate au... how about they each have their soulmate's eye color that automatically swaps back to their original own as soon as their eyes meet??? i think it'd be an interesting idea. since avgins are known for their unique eye color, i think dr ratio possessing them puts him in a spot where he firsthand witnesses discrimination they have to go through. he knows for sure the eye colors don't belong to him— one look at his parents is enough— and he'd also get comments like either "oh... your soulmate is a...?" or "tch, you vermin, get out of my way." (they may have mistaken him as an avgin due to the eye) and it just makes dr ratio even more protective of this soulmate he has never gotten to seen before.... and imagining when ratiorine first met, as soon as their eyes lock and swap, ratio was in complete awe as he stares stunned at churin. he had always thought the eye color itself is pretty, but seeing them in their full glory on aventurine... it was a whole another captivating sight to behold 🥺