Okay so I want to start by say thing that the whole thought of the card and how the ability works is amazing. The way you combined those two cards, Guardian Angel and Arch angel, with Innocent and Martyr is fantastic, no joke. I love it.
Second of all, the card art is great and really paints a picture of what the card is and how it works.
Third of all, you are correct and i think that this card can be a part of many decks, using immo, lighting and various killing spells. Though i feel as if the life should be only 2 so that it becomes more versatile, for Otyugh and all bolts to be able to kill it. Also, i think that the cost of the Martyr should be just a little higher because i think it is all too easy to get the Arch Angel out. 2 SN + 1 Lighting = Arch Angel. So i think the cost of the Martyr should be 5. The Innocent card is only one lower than the Gaurdian Angel so I think the Martyr should be like that too.
Overall, great card, i love the thought into the card and I hope it does well later on in votes.