Complex sentence: He is well known as a one-eyed douchebag Richmond supporter, who makes himself feel superior by badmouthing every team that isn't Richmond, but is renowned for his attitude problems in regard to West Coast, Geelong and Essendon.
Split into simpler sentences: He is well known as a one-eyed douchebag Richmond supporter, who makes himself feel superior by badmouthing every team that isn't Richmond. However, in this sense, he is primarily renowned for his attitude problems in regard to West Coast, Geelong and Essendon.