"He has no need for combat training - He can freeze time and space - as he often reminds us."
In case you forgot, Sylar was not affected by freezing time.
At the end of the episode, Sylar said to Peter "They said I blew up the city, but we both know that's not the truth, don't we." Combine that with Isaac's paintings and Peter's vision of himself blowing up....So the question isn't who will blow up, it's can the future be changed or are Isaac's paintings set in stone? If they are set in stone, then Sylar will die by Hiro's sword and Peter will blow up New York."
True, but the "future" may be changed now that "Hiro" has gone back in time with his prior knowledge. I remind you that he had the comic book at the beginning of the series, and yet knew nothing about killing a man. Surely, he (like any one of us) would have looked at the end of the comic book as soon as we got it, to see what would happen next. "Future" Hiro came from a time where the cheerleader was killed, and Sylar got the healing power, making him almost impossible to kill.
THAT timeline no longer exists. Based on that reasoning, the artist's painting of New York exploding came from the
second timeline. I'm guessing that after "current" Hiro came back, more things will change from what they
might have been. I wouldn't necessarily confuse Peter's dreams with the paintings of the future. They could simply be his worst fears, rather than actual premonitions, and the painting shows
someone blowing up, but we really don't see
who it is. It
could be that Sylar ends up blowing up, or no one blows up as well.
IIRC (I'll have to go back and watch to double-check), I seem to recall that there was a painting showing the cheerleader on the steps with "Sylar" looking down on her, but when it came to that point in time, it was
Peter in that actual position. I swear I remember pointing this out to my wife.
The future can be changed. Even Isaac told Sylar they will stop him. I doubt he was referring to the "future" that Hiro just came back from. Otherwise, why not just let things run their course?
"We have to take anything we saw / learned in "five years gone" with a grain of salt. But one thing we did learn was that Future Hiro had altered the course of events and the city still blew up."