Linderman seems to know something about the heroes, but what?
He is involved in nearly every facet of every hero's lives.
It's obvious that he's powerful bad dude, but he seems smart and one step ahead of all the heroes in a game that they are not even aware exists.
He collects Isaac's prophetic art and now has Hiro's sword, on top of having dirt on nearly every major character in the story and hasnt even appeared yet.
When he makes his appearance the only actor I can see doing that character justice is David Carradine.