Complex sentence: The last known dragon, Tintaglia, is overseeing this journey in the hopes that dragons will be reintroduced to the world; the Rain Wilds Council has agreed to help in exchange for her helping the Rain Wilds people in their war against Chalced.
Split into simpler sentences: The last known dragon, Tintaglia, is overseeing this journey in the hopes that dragons will be reintroduced to the world. The Rain Wilds Council has agreed to help in exchange for her helping the Rain Wilds people in their war against Chalced.