Complex sentence: With Bumblebee forced to take cover from Sentinel's attack, Ironhide dies, he rusts and breaks apart, however, in the end, Optimus avenges Ironhide's death by executing Sentinel.
Split into simpler sentences: With Bumblebee forced to take cover from Sentinel's attack, Ironhide dies as he crumbles to rust. However in the end, Optimus avenges Ironhide's death by executing Sentinel.