The Chucky in this movie is not the one from Child's Play 3, but a destroyed clone created either by regeneration at the Good Guy factory or the rite that Chucky would later make use of in Cult of Chucky.
What else could explain the fact that it doesn't have the section of its face sliced off as it was in the previous movie?
http://tvtropes.org/pmwiki/pmwiki.php/WMG/BrideOfChucky
FollowingWMG / Bride of Chucky
Go To
