Complex sentence: Deadman questions why the Lantern has taken him to Aquaman when he should be searching for the Entity's replacement, and the ring replies that to find the new Entity, Deadman must help all the other resurrected complete their tasks.
Split into simpler sentences: Deadman questions why the Lantern took him to Aquaman when he could be searching for the Entity replacement. The ring replies that to find the new Entity, Deadman must help all the other resurrected complete their tasks.