I'm sure this had been asked, but surely Sahkil Tieflings and Manasputra Aasimar exist but just aren't statted yet right?

I-- hm

Well they-- hrrmmm

Maybe... Both of these Outsider don't feel like the kind to intermix with mortals for different reasons, and the only reasons I could conceive a Sahkil yielding a child are deeply unpleasant in ways I do not wish to contemplate or voice (similar to why daemonspawn exist despite a daemon's stated goal to be total extinction of life).

They likely do exist, and my attempts to find lore details on if they were even possible brought me to this page by thecreaturecodex where they create stats and lore for Sahkil-tieflings. To my knowledge, Manasaputra Aasimar aren't even hinted at as a possibility, though the Manas themselves are quite welcoming to any mortal who braves the journey to the Positive Energy Plane to speak to them. It's not out of the question.

Perhaps that's where astomoi come from, rather than aasimar?