Complex sentence: Windfang was once a human general named Venturas from Koth that opposed Wrath-Amon 200 years before the events in the series, but was captured and mutated by Wrath-Amon.
Split into simpler sentences: Windfang was once a human general named Venturas from Koth that opposed Wrath-Amon 200 years before the events in the series. Venturas fought on, but he was captured and mutated by Wrath-Amon.