Complex sentence: In Wagner's opera cycle Der Ring des Nibelungen Alberich is a composite character mostly based on Alberich from the Nibelungenlied and Andvari from norse mythology.
Split into simpler sentences: In Wagner's opera cycle "Der Ring des Nibelungen", Alberich is a composite character. He is mostly based on Alberich from the "Nibelungenlied", but also on Andvari from Norse mythology.