Before turning his attentions to mugen, Zadkiel was mainly known as a PSN Profile skin editor during the hay-days of PS3.
Zadkiel has been active on youtube since atleast 2008, however his presence in the Mugen community began around late 2016.
As of September 2018, Zakdiel changed his screen name to AnimugenZ.
Zadkiel is best known for his Zadkiel Mugen channel, and his KOF XI UM style KOF/SNK character edits.
However, it is noteworthy that he is also makes many semi-decent stages, and various video tutorials on things like color separation & portraits.
Zadkiel can be likened to past quality KOF character editors like Kamran Bernstein - he not only works very fast, he edits uncommon characters, previously incomplete characters, of characters that were previously only made to work in moleboxed KOF fullgames.
He is very active and releases characters and stages regularly.
As of 2018 he appears to be working on his own KOF fullgame project in Pseudo-XI/UM/XIII style titled KOF Dimensions