Let’s say it at once: in my eyes, the drawings were far from awesome. But… I don’t know, I still loved them, maybe because I felt fondness for the characters inside ^^
It may also have helped: I’m a huge Smash Bros Ultimate fan, and Pyra/Mythra are my favourite characters to play with, their rich playstyle allows to always have a chance at victory without being hopelessly weak against certain enemies (for instance, as a Ganondorf lover, the only character I always manage to bring back in Elite, I cry whenever Ness appears) , it’s always fun to play them 
Well, there you go, a decent but not exceptional Pyra + Mythra + Rex doujinshi, a threesome at an onsen (their clothes subtly transformed into swimsuit versions… that, that was hot!), see for yourselves for the rest, and thanks to Doujin-Moe!
