Complex sentence: Also living at the Bannon Ranch is Hud's teenage nephew Lonnie (Brandon De Wilde), the son of Hud's deceased brother... who died as a result of Hud's recklessness; this is the primary cause of Homer's anger and resentment toward Hud.
Split into simpler sentences: Also living at the Bannon Ranch is Hud's teenage nephew Lonnie (Brandon De Wilde), the son of Hud's deceased brother who died as a result of Hud's recklessness. Hud believes that his brother's death is the primary cause of Homer's anger and resentment toward Hud.