Complex sentence: As the sun rises, Shrek begins to fade from existence, but Fiona, having fallen in love with him, kisses Shrek just before he disappears, thereby voiding the contract and restoring Shrek to his world, just before he lashed out at the party.
Split into simpler sentences: As the sun rises, Shrek begins to fade from existence. But Fiona, having fallen in love with him, kisses Shrek just before he disappears, thereby voiding the contract and restoring Shrek to his world, just before he lashed out at the party.