Complex sentence: In "Clean Sweep", however, Sean and his mother are both saved by Nikita when the rest of Oversight is killed, and so they team up with Nikita, Michael and Alex to in the hopes of destroying Division.
Split into simpler sentences: In "Clean Sweep" Sean teams up with Nikita, Michael and Alex to save his mother. At the end of the episode Nikita and Michael agree to team up with Sean and his mother in the hopes of destroying Division.