Ancient Ruins Under Pelpuli

While exterminating a nest of basilisks, the party uncovered a recently dug hole, presumably by the Congregation due to its Oflycus corruption and it being done recently. Inside was an ancient ruin with a trapped hallway leading to a tomb. Along the stone walls were carvings depicting a humanoid race, unfamiliar to those today, with proportionally long slender arms and large heads. It was discovered that this race was presumably what was once the Illithid race, now named the mindflayers.
The carving along the back wall depicted a large orb being held by a prominent looking figure, with other figures bowing to it. In the middle of the room lies a pedestal that appears to have once held such an object, however is absent now. After some investigation it was discovered that the orb, now absent, was some sort of great orb of power and is likely from another plane. These orbs contain very powerful enchantments that can vary from every harmful to very helpful, and anywhere in between. The icronogrify was also religious in nature, however not having anything in common with the Lustinian pantheon.
There is also obvious signs of Oflycus corruption, with the beginnings of a Saftrick tree growing and small sacs looking to contain the fetuses of plagulings and plague thralls. These were burned and destroyed.
Later upon returning to Pelpuli the party discovered that the ruin was being excavated by two prominent figures of Lustinia and Marintia, Hubert Saltspyre and Haldran Mousion respectively. There was an unspoken conflict between the two, however the party remained neutral.
When delving into the ruins many things were discovered, that they worshiped Val'Nia, there was a map room (which was eventually wiped from the parties memories) as well as a separate structure connected to the ruins. This separate structure was a black door leading to an ominous chamber, opened by the Kenku accompanying Haldran.
It was discovered that whatever was within the crypt was unleashed, urging the party to track down the mind flayer and slay it. In the fighting the entire Seldonian force within the cave was slain, as well as Hubert Saltspyre, one of the most prominent generals of the Theocracy. The mind flayer itself was slain, wearing a breastplate of an unknown material. When the party fell unconscious Haldran rewrote their memories, wiping evidence of the map room and framing Saltspyre as the more suspicious one.