MGS4 meets Zelda?

I would very much prefer to see a dark Zelda game. I understand that Link is always a boy or teen, but why can he never be this grizzled combat veteran, like someone who's fought in the equivalent of Crusades?

I thought Twilight Princess made a huge stride with this simply by allowing Link to use some brutal finishing moves on downed enemies, but I'd love to see a game with a very dark and morose theme, and Link just being a brutal mother****er. Kinda like him saying, once and for all that he's done with Gannondorf and will just end shit once and for all.