Complex sentence: After discovering Casper's absent, Kibosh becomes furious about the idea of letting a rookie ghost being let loose without any education to which he forces his spineless assistant Snivel to find Casper and bring him back.
Split into simpler sentences: After discovering Casper is absent, Kibosh becomes furious about the idea of letting a rookie ghost being let loose without any education. He forces his spineless assistant Snivel to find Casper and bring him back.