Yay, it's Lacus! I absolutely love this. Actually, the lyrics you picked are perfect for him, and I just love the images (I have that soundtrack of the Yu-Gi-Oh movie and still love it). I have actually learned a little of his backstory now if you're interested too:

Lacus used to be a human. One day he met a boy named René Simm. Lacus decided to take him in as a brother, but René only saw him as a half brother. They grew up together, and one tragic day, they were both shot. Then some vampire nobles came and gave them blood, so they lived to be vampires now currently serving as city guards. - Owari no Seraph Wiki. (They've been accurate, so this is more than likely true).

I hope if they do another season they'll elaborate on Lacus and Rene. It's interesting to learn more about characters like them, considering they're part of the main vampires they show. Besides, Lacus seems like a complex character, and I love that