Sylar originally had to get their power from inside their brain. He's learned compassion and can now take powers without cutting off the head. But the evil bastard has gone back to his old ways of poppin open a can of Pringles for his newly desired powers.
Cutting off heads = ratings Giving hugs and taking powers = gay. Go Sylar... or wait... is it Spock from the Star-Ship Enterprise? Wrong show.
