What Anime is this picture from?

[Gantsu]

I saw this picture several times, but I could never get an answer from the ppl I asked. The freak in the pic looks creepy cool. I think, I'll watch it just for him.

 

[nawi]

the white haired man is accelerator from toaru majutsu no index series he also appear in toaru kagaku no railgun

 

[Gantsu]

Finally. thanks so much. I'll probably watch this anime. Especially considering he's one of, if not the most powerful char in the series. Plus he's a sadist, so he seems to have no redeeming qualities about him. I read the MC's description, and he seems like a turn off, but I think I can work thru that.