*g* Pretty much, read anything that icarus_chained wrote that has Tony in it. I mean, now that I think of it - icarus_chained's noir series is also pretty dark Tony. And, the Locks one shot sort of implies a dark Tony. And icarus_chained's Tony/Loki series is pretty dark.

...actually, you probably have a good chance of getting at least ambiguous Tony if you sort AO3 by Tony/Loki...