Complex sentence: After being told to destroy the Master System by the Master, he battled and defeated Sera, but his damage was so extensive that he was forced to have his memory removed and placed within Data, and be reset to the configuration of a newborn baby.
Split into simpler sentences: After being told to destroy the Master System by the Master, he battled and defeated Sera. However his damage was so extensive that he was forced to have his memory removed and placed within Data and was reset to the default configuration of a newborn baby.