How to Stop an Exploding Man - S1-E23
Continuity mistake: When Parkman is shooting at Sylar in Kirby Plaza, he fires four shots. But when we see the bullets hovering in the air before Sylar's hand, just before he flings the bullets back toward Parkman, there are five of them. (00:35:30)
How to Stop an Exploding Man - S1-E23
Continuity mistake: Hiro's sword changes position between the shot in which Hiro arrives to the scene and the shot when he is about to kill Sylar.
Chosen answer: It's not been made 100% clear. It was originally assumed that he actually consumed part of the brain, but this has turned out not to be the case. Sylar has been shown all along to have an instinctive knowledge of how things work and how to fix them - this is his actual original power and the ability that made him an exceptional watchmaker and repairer. It appears that he uses a similar process when acquiring new powers - he exposes the brain of the target, allowing him to examine it and determine how their power functions. He can then apply that knowledge to his own brain, allowing him to replicate the ability in question.
Tailkinker ★