In the previous session the group had explored The Labyrinth and fought a demon lord to get a drop of his blood. Back in Araj they got contacted by Basidia, the un-corrupted ruler of the myconids, to warn them that the Fetid Wedding is about to start, a ritual in which Zuggtmoy attempts to use a distorted wedding ritual to take control of Araumycos, a continent-sized fungal life-form.

Teleporting there, they get some help from Basidia: They let themselves get infected by spores which enable them to make mental contact with Araumycos, and at the same time protect them from the corrupted spores of Zuggtmoy. However their meeting with Basidia gets interrupted by an attack of oozes, three black puddings and two ochre jellies, which reminds them that Juiblex is still around and an old rival of Zuggtmoy. Trying to make contact with Araumycos triggers his defenses, as he has trouble telling friend from foe due to Zuggtmoy's corruption. So the group fights four fungal otyughs, again without much trouble. Then they persuade Araumycos that they are friendly and get transported into a dream plane. There Araumycos exists as a mountain-sized brain in a giant stone skull, and he asks them to enter the skull and cut out the part corrupted by Zuggtmoy.

However Zuggtmoy interferes and appears in the dream, attacking the players. Although her spore attacks don't work, she is still a very powerful opponent, and the group only beat her with quite some trouble and several characters down. They then cut out the corruption and free Araumycos from Zuggtmoy's influence. On leaving the dream they realize that they are still in the same state as they were before they entered, and the dream fight wasn't "real", and didn't banish Zuggtmoy. However the wedding has been crashed by Juiblex, and the two demon lords are battling it out in the distance.

By the time they get there, Zuggtmoy has been defeated for real, and banished back into the Abyss, while Juiblex is still standing, but weakened from the fight. So the group attacks Juiblex, especially Arkoy, who has history with him. Arkoy tries to summon a divine intervention, and succeeds. The intervention comes in the form of a powerful banishment spell, which Juiblex can only resist if he rolls a 20 (and he doesn't have any Legendary Resistance auto-succeeds left). However Juiblex still has advantage on all saving throws, and manages to roll a 20 on one of the dice, resisting the banishment. Combat commences, but Arkoy in the next turn casts his own banishment spell, and this time Juiblex rolls low, and gets banished back into the Abyss. With this big success, two demon lords gone, we ended the session.

(I gave the group the choice to either make haste and play through to the end of the campaign in this session, or to stop early at this point and still have enough material for a final session.)