Katsute Kami Datta(Many male monster TF)
 

This anime has only aired three episodes so far, but all of them feature at least one detailed transformation into some kind of huge monster (Giant dragon, some sort of reptillian Ogre, a werewolf and it seems many more)

There are also a couple of females who can transform, but not much of them has been shown process wise.

Re: Katsute Kami Datta(Many male monster TF)
 

Thank you AP Ninja!

Katsute Kami DattaMany male monster TF
 

I know, how it is necessary to act, write in personal