Complex sentence: Deathstroke walks away with his son, but Jericho possessed him disgusted at what his father did to achieve his restoration, intending to destroy first the Methuselah Device, then himself and Deathstroke.
Split into simpler sentences: Deathstroke walks away with his son, but Jericho possessed him, disgusted at what his father did to achieve his restoration. He intends to destroy first the Methuselah Device, then himself and Deathstroke.