Disregarding homebrew adventures and other 3rd party content, two adventures have you facing demons. • Out Of The Abyss has plenty of demonic influence throughout the first half as the players are escaping the Drow prison and making their way through the Underdark. Including an encounter with Demogorgon himself! The second half has the player and their allies taking part in an invasion of the Underdark to fight the demonic princes themselves. • Descent Into Avernus has the players dealing with a cult at Baldur’s Gate and eventually needing to find a magical sword that belonged to an angel seeking to end the Blood War. This takes the party down to the first layer of Hell, complete with Mad-Max-style death machines, political intrigue, and some of the biggest and bloodiest battles of the Blood War. Of course, there are more official adventures that have you facing demons and devils alike, but those two stories have demons, the various demon princes, devils, and the Blood War as the main characters and background events. Plus, they are both very fun to play with at a dedicated party!