Complex sentence: The children kill them with the help of an army of skeletons from the ship, all led by Enoch, while Emma holds off Barron and Jake frees Miss Peregrine and other captive Ymbrynes.
Split into simpler sentences: The children kill them with the help of Enoch by using an army of skeletons from the ship. While Emma holds off Barron and Jake frees Miss Peregrine and other captive Ymbrynes.