Board Thread:Fourth Databook/@comment-4271790-20141104211032/@comment-8174280-20141104234229

Honestly, I assume medical jutsu are Yin and Yang. And I believe Kekkei Moura is basically the ability to mix 4+ bloodlines at once, while Kekkei Touta is mixing 3 bloodlines, and Kekkei Genkai is mixing 2 bloodlines (I wouldn't necessarily say bloodlines, but different natures and techniques).