Board Thread:Questions and Answers/@comment-24204539-20140117223432/@comment-11005605-20140118043946

Heavily implied to be Asuka's future White World self. The Four Archangels (as well as the other notable groups) seems to to use a name inheritance system, this is where the acronym comes in Uriel A.T. = Uriel Asuka Tennouji Michael S.K. = Michael Sakura Kamiyugi. There's also the Pendragon Apostolic Church's legend and Uriel having a similar halo to Fierte (and the card's effect requirements).