Complex sentence: The third was Suk-jin's he planned a special prison so that the members can feel what it feels like, eventually, the mission was escaping from prison to attend Suk-jin's renewal vows on wedding party with his wife.
Split into simpler sentences: The third was Suk-jin's and he planned a special prison for the members. In the end, the mission was to escape from prison and attend Suk-jin's renewal vows with his wife.