Complex sentence: She has always stood by him, besides his foibles because she knows he is a good human being, she is even ready to fight her dad, who is against Shantanu as he perceives him as a spoilt brat, failing to see his good side.
Split into simpler sentences: She has always stood by him, besides his flaws because she knows he is a good human being. She is even ready to fight her dad, who is against Shantanu as he perceives him as a spoilt brat, failing to see his good side.