Insithryllax

Insithryllax was a great wyrm black dragon who was present in Innarlith in the mid–14 century DR. He was a close friend of the Thayan Red Wizard Marek Rymüt, with whom he assisted a project to breed a mutant cross between a black dragon and a firedrake.

Personality
Insithryllax was quite comfortable with polymorphing into a human form, which he often did and he used it to enter human society.

Relationships
Marek had once cast a charm monster spell on Insithryllax during a battle and enthralled him. The spell eventually wore off, but the two of them had developed a natural friendship that lasted for decades. Insithryllax accompanied Marek to Innarlith when the Red Wizards sent him as their agent to the city. While Insithryllax was enthralled, other Red Wizards had seen him as either an asset or a threat, depending on their relationship with Marek.

He became the father of a number of offspring when he bred with female firedrakes as part of Marek's project to breed black firedrakes. However, he didn't have any deep care for his offspring and would feed them to each other when they ran out of food in the nursery.

History
In the 1330s DR, he was residing in the swampland of Surmarsh in Thay, where he had a tribe of lizardfolk who obeyed him. However, this tribe had failed to pay their taxes to Thay and as a result the Red Wizards sent Marek and others to go after them. Marek and his comrades battled the lizardfolk before Insithryllax appeared. Marek used a charm monster spell on Insithryllax and enthralled him. Insithryllax then returned with Marek to civilization in 1336 DR and eventually wound up with him in Amruthar, where Marek would receive his orders from the tharchion to go to Innarlith.

Marek was sent to Innarlith in 1340 DR and Insithryllax accompanied him. The charm monster spell eventually wore off in the years that followed, but Insithryllax chose to stay with Marek.

Eventually, Marek concocted an idea to try to breed the mutant offspring of Insithryllax and female firedrakes, which he called "black firedrakes". Marek found an underground area beneath the sewers of Innarlith that had formerly been used as a thieves' den and made it into a nursery for raising the young. Insithryllax mated with the female firedrakes and had many successful offspring with them.

However, Marek had underestimated the amount of food that the black firedrakes would consume and this led to them needing to devour each other in order to survive. Insithryllax maintained an order to this by killing off weaker ones to feed to the others.

In 1361 DR, some of the black firedrakes found a way to escape to the surface, where they created destruction and mayhem across the city of Innarlith, before they were either killed by the city guard or transported back to the nursery by Marek. Eventually, Marek concocted a new plan where he carved a pocket dimension out of Fury's Heart that he called the Land of One Hundred and Thirteen and used this to raise the black fire drakes. Insithryllax then went to the pocket dimension to help with raising the offspring.

Insithryllax assisted Marek with creating an army of black firedrakes, which Marek used to help Senator Salatis with overthrowing Ransar Osorkon of Innarlith in 1365 DR.

In 1368 DR, Insithryllax killed a water naga in the Nagaflow by diving on it from a high altitude. He then went with some of the black firedrakes to attack the caravan of the ambassador from Arrabar on his way to Innarlith. They killed the ambassador and all witnesses, while purposely avoiding the use of their acid breath weapons. Insithryllax then left the body of the naga he had killed at the site to give the impression that it was the nagas of the Nagaflow who were responsible for the attack.

During the Rage of Dragons that occurred in 1373 DR Insithryllax fell under the effects of the rage, which filled him with burning anger and almost led to him destroying Ransar Pristoleph before Marek intervened and transported back to the Land of One Hundred and Thirteen. Marek kept him in the pocket dimension until he had figured out what was going on. He then explained to Insithryllax and Insithryllax insisted that he be allowed to go free back to Toril. Marek was concerned that Insithryllax might cause a lot of destruction, but after Insithryllax agreed to go back into human form, Marek consented and brought him back to Innarlith. Insithryllax then departed from Marek and flew away to head home to the Surmarsh in Thay.

Appearances

 * Whisper of Waves
 * Lies of Light
 * Scream of Stone