Two-Face is a well known Batman character who's real name is Harvey Dent.
Somebody's been tagging it as Two_Face instead, but the official spelling is Two-Face. Two_Face should be aliased to Two-Face.

Aliasing Two_face to two-face is good, I think you're completely correct there. But I'm not sure if we should implicate Harvey_dent...

I feel like alter egos shouldnt be implicated bh the super hero/villain tags. The reason I say that is because what if someone is cosplaying (or a character is dressed up as) a super hero? Would having the alter ego tagged make sense in that instance? Also, what if you're just looking for pictures of superman but not Clark kent, or vise versa? I think that implicating those together would make it difficult to get good, specific searches. But I may be totally wrong on that one.

That's exactly why they shouldn't be implied, Tokaido.