Gardian Angel Au - Tumblr Posts

Can someone tell me who originated the gardian angel AU and this Lucifer design please? So I can credit them properly (thank you ^^)

( From what I've heard) the concept of a gardian angel and design Belong to @notherpuppet

But then who originated the concept of human Alastor and Angel Lucifer if it's not called gardian angel AU? (Because that's the real thing that inspired me to combine with the other inspiration below)

Need I say more? XD