User blog comment:Viper 121/What, I still do these things?/@comment-25399827-20150711163516/@comment-26228098-20150727190349

That would be monster genes in Alice, I mean Lucifina and Marcellus looked pretty much same height so it be normal for Luka(hehe called him his japanese name last time) to be a bit of a shota in his teenage years(we only know he's younger than alice who's 21).

Alice on the other hand is a pretty long(tall) ass snake, and quite tall in her human side wise when compared to Luka too so add that with the fact that she also carries genes of all monsters in her you could say that Nero is half human(Both Luka and Alice are 50% humans so..), one part angel and then thousands of smaller parts of other monsters, among those being those big ass sandworms(building sized oppai!), dragons and behemoths(fairies too!), and his life must have been filled with girls chasing his ass so his body must have adapted along.

Some of those tiny bits MUST have passed on..