This also developed after the ratings of Darna has gone to a slowdown. The show's producers thought there must be new excitement that will be brought withing the show and one of the things they thought was bringning Katrina's character to the show as soon as possible.
Katrina's character was originally scheduled in later part of the show but due to the above mentioned problem in the ratings, they agreed to put her earlier hoping to improve their showing in the ratings.