Complex sentence: He is an engineer who befriend Jack and Hannah after they saved his people and their settlement from a rogue Shivat, he becomes one of their allies in their fights for survival in the post apocalyptic world over run by Dinosaurs and Saber Tooth Tigers.
Split into simpler sentences: He is an engineer who befriends Jack and Hannah after they saved his people and their settlement from a rogue Shivat. He becomes one of their allies in their fights for survival in the post-apocalyptic world overrun by Dinosaurs and Saber Tooth Tigers.