Second Treachery

The Second Treachery is a major event in the Legendaria. It is defined as when Zehir acted as a double agents against his fellow Gods for the Primordials.

Story
When Tharizdun convinced the Primordials to wage war on the Gods, they charged into the Prime Material Plane to face their foes, but Zehir, ever a step ahead, got to them first. Instead of warning his pantheon, Zehir made a deal with the Primordials: he would allow them to reach the Gods undetected and aid them in their fight, in exchange for a position of power. The Primordials agreed, and true to his word, Zehir gave the Primordials a notable advantage in the early ages of the war.

It is said that Zehir was particularly distasteful of Io, and played a key role in his death. He claimed to bless Io with greater strength, but in actuality poisoned him, making him weaker and leading to his death at the hands of Erek-Hus. His plan failed when the two halves of his corpse rose up as Paladine and Tiamat, but Zehir nonetheless stuck to his alliance with the Primordials. It is also believed that he may have been the cause of Mystra's death as well, intentionally causing Rorn to go into a fury and kill her. He likely did this as the war ending in a truce would not grant him the power he coveted.

Eventually, at the end of the Dawn War, the Primordial Ubtao appealed to the Gods, offering his own knowledge to them, in exchange for his preservation. To prove himself, he not only revealed the location of the Primordial fort of Glaur, but ousted Zehir as a traitor. At the accusation, Zehir attempted to talk his way out of it, but the Gods began to see the truth in Ubtao's explanation. With no other options, Zehir attacked Ubtao, and the two fought before Zehir was eventually killed, ending his schemes for good.