Complex sentence: Thomas Covenant, who must struggle with his memories, takes the Krill from its place in Andelain, however his former wife Joan is able to attack Covenant with wild magic, through the Krill.
Split into simpler sentences: Thomas Covenant, who must struggle with his memories, takes the Krill from its place in Andelain. However, his former wife Joan is able to attack Covenant with wild magic through the Krill.