Complex sentence: Dean tortures him on Castiel and Uriel's orders in the following episode for information about a string of angel murders, but the demon refuses to disclose any information on that and instead reveals that Dean torturing souls in Hell broke the first seal.
Split into simpler sentences: Dean tortures him on Castiel and Uriel's orders in the following episode for information about a string of angel murders. However, the demon refuses to disclose any information concerning the murders, choosing instead to reveal that Dean's wicked actions in Hell broke the first seal.