Complex sentence: Eleanor follows him, determined to help him, only to almost be attacked by Mr. Talbot, who was the original werewolf that bit Theodore, who quickly defends her and attacks Mr. Talbot, biting him during the struggle.
Split into simpler sentences: Eleanor follows him, determined to help him, only to almost be attacked by Mr. Talbot, who was the original werewolf that bit Theodore. Theodore quickly defends her and attacks Mr. Talbot, biting him during the struggle.