Basically, Thragg's breeding process is incredibly brutal (the massive size gap is an obvious factor, ofc) and Mark ends up serving as nothing more than a vessel for Thraggโs seed :D
By the way, this reminds me of a Thrark fic on Lofter (abo AU, ofc). So, one day, itโs revealed that Mark is an Omega, and Nolanโs just like, "viltrum will rise!" He alerts the Viltrumite army, and they come to take them both away.
They canโt manage to separate him (the omega) from *his* (alpha) father, so Nolan has to go in with him, staying there to hold his own son for Thragg to do his work.
A day before I drew this, I my friend on Discord mention how difficult it is to draw feet. She said that since feet are rarely seen, whenever people have to include them, they just put socks or shoes on the character to avoid having to draw the feet themselves๐งโโ๏ธ