Avengers VS X-Men Event

Origin
The Phoenix Force returned to earth seeking Hope Summers. The Utopian X-Men, lead by Cyclops wanted Hope to be joint with the phoenix. However Thor and Tony Stark together broke the Phoenix in five pieces. It was infused with Cyclops, Emma Frost, Namor, Magik and Colossus.

Trouble in Paradise
The X-Men created Paradise on Earth. However the Avengers mistrusted them. Their mistrust was proven correct when Namor invaded Wakanda. He destroyed much of Wakanda, but he lost the battle and his portion of the Phoenix Force. This portion reverted to the other four members. Thor was able to take the Phoenix Force from Magik and Colossus. Emma and Cyclops were the last remaining. However Cyclops turned on Emma and became Dark Phoenix. Hope and Scarlet Witch then took him down. However not before Cyclops killed Charles Xavier. The Phoenix Force the materialised seperately in the form of Jean Grey and disappeared. Cyclops was then imprisoned while his allies became fugitives.