P-P-P-POW!

I've been watching Season 2 of Heroes and I've got up to the bit where we find out who Adam is. So don't read if you haven't seen it but are watching...
How is it possible he is Takezo Kensei?!
In 1671 he is killed when the gun tent sets alight which is weird as his power is regeneration. Did he manage to heal himself and continue living forever?
He left Peter a note that gave the impression they were friends during the missing 4 months of Peter's life. Could Peter have perhaps gone back in time, met him and brought him to 2007? Or did Hiro go back for him? Perhaps it was just the regeneration thing.
Meanwhile, Noah Bennet wants the family to move away again after Claire is 'exposed' following the cheerleader incident which was printed in the newspaper and Molly Walker is awake.