Ithvar's ruin was his temper, he was too ready to fight without thinking for a second. He was also very ambitious and did not trust other wizards. He knew that Ysele would betray him in the future, but for the time they collaborated.
Born into power and privilege as the son of an illustrious family of Cormyr, Ithvar from a young age showed an incredible talent in magic. Tutored by the best teacher available, he soon become a great mage and joined the War Wizards of Cormyr. However, thanks to his hot blood, he killed a superior during a dispute. His family's connections got him out of jail or a death penalty, but it was suggested that it would be better if he left the country.
Ithvar wandered for a time until he settled in Skullport. There, he joined the also recently arrived Aurin. They formed the Hired Horrors business with Chantos Graybeard and Ysele the Cat. Being the major investor, Ithvar believed he should be the boss but Aurin, who'd captured the deepspawn, contested this. They decided to settle the matter with a magical duel, but not only did Ithvar lose but Aurin saved his life. From that moment, Ithvar waited for the right time to get revenge. By 1370 DR, he'd recently allied with Ysele in his plot, but Chantos resisted all suggestions.