Hello!
Over the past few weeks, my friend has made it kind of a mystery as to who her favorite character from a series is, and it's been driving us all crazy, haha.
I have no clue what the series is and my searches have all ended up as dead ends; help finding this character would be well appreciated.

Information:
- Male
- From an anime
- Antagonist that later receives a redemption arc
- Shares a name with a Fire Emblem character (though I could be wrong, I've managed to narrow it down to either Odin or Legion) (http://fireemblem.wikia.com/wiki/List_of_characters_in_Fire_Emblem_Heroes)
- Apparently shares a name with a persona from Persona 3 (see above) (http://megamitensei.wikia.com/wiki/List_of_Persona_3_Personas)
- Occasionally wears a helmet
- "he's blue"
- "and when i say he's blue
he's not usually blue
but when he is blue
he's REALLY blue"

Thank you in advance if anyone does recognize/figure out this character!

[ Edited Nov 23, 2017 ]

Hmmm...

To me this character sounds a lot like Loki Laufeyson from the anime The Avengers.

Although, I could be wrong. I'm also thinking of him in the Live Action movies as well.

You could try and guess this character, it's worth a shot.