Complex sentence: After being sent from the Underworld, he managed to take over Buckland Auction House, with a fellow Warlock, Hannah Webster, in order to acquire the powers of the Charmed Ones.
Split into simpler sentences: After being sent from the Underworld, he managed to take over Buckland Auction House, with a fellow Warlock, Hannah Webster. Their mission was to acquire the powers of the Charmed Ones.