In the Year of the Spouting Fish, 922 DR, Strongor convinced Chardansearavitriol, a black dragon known as Ebondeath, to become a dracolich. He provided the magical assistance needed for the transformation.
Following the creation of the dracolich, Strongor presided over members of the new Ebondeath Sect, which resided in the Mausoleum of Ebondeath that they'd created beneath the ruins of the Uthtower. As their leader, he led the sect in a unique perspective combining the teachings of Myrkul with those of Sammaster. He preached that Myrkul would absorb the mortal world into his realm. The gods of the living would be discarded and a new pantheon of dracoliches would ascend. He resided at the Mausoleum for the remainder of his life.
In the Year of Flashing Eyes, 929 DR,[note 1] a young, ambitious cult member conspired against Strongor. He hoped to not only kill the leader, but also trap his soul in the weapon that slew him, an enchanted obsidian-bladed dagger. This cultist was successful in his ambition to kill Strongor, but it was unknown if his plans to trap Strongor's sentience in the dagger were successful. It was also unknown what became of the assassin, though he may have perished in the attack.