In Curse Of Strahd, the Pack in saw Izek in the Vallaki Town Square while setting up posters for the next festival, though he paid them little notice until Vampire Spawn broke out across town. After chasing the vampires while hurling flames with wild indiscretion, he lost a one-on-one fight with a thrall, but was healed by Ghalwin Forrester.
The attack caused the burgomaster to increase his personal guard, resulting in Izek's resources being spread thin. Weeks later, stressed over an upcoming full moon, he was again approached by The Pack; this time, they inquired on Ireena, having learned of his bedroom. An increasingly-agitated Izek looked to run from the questions, and was driven to panic when it was brought up that Ismark Kolyanovich was Ireena's brother. He tried to run, but Ghalwin misty stepped to him, and he relented the stories of his dreams to the group.
The next day, the long-scheduled Festival of the Blazing Sun finally occurred, and led to the Riots Of The Blazing Sun. The Baronet Viktor Vallakovich ordered Izek to attack Atlas Atruvian, who was blocking his way as the town called for the heads of the Vallkovich family. Izek did as told, bringing his flaming axe onto the old cleric, but during the melee was hit by waves of confusion spells from Viktor: he was collateral damage in the wizard's way. Unsure of what to and who to protect, Izek ran from the scene, and left his adoptive family to die.
After this, Izek ran west, fighting off the roving horrors of Barovia and nearly dying on his own. However, he encountered unlikely allies in a group of hill-folk, who saw his arm as a sign that he had been blessed by Strahd himself. The hill-folk took Izek to the cursed Gulthias Tree at Yester Hill, and the site of the Mountain Fane dedicated to the Ladies Three. In exchange for protection and Common translation services, the elders allowed him in. At the hill, he formed a bond with the scout leader Helwa over their mutual strength and off-putting social skills.
Elders in the hill tribe deduced that Izek's arm was not Fiendish, as he had been taught to believe, but rather a miracle of ancient Giant magic; they taught him to harness this power, channel it to enlarge his body, and command different elements. Though they only spoke broken Common, Izek communicated with them through action, defeating their Barbarians in feats of strength and defending their druids from other tribes. He spent his time attempting to hunt Sangzor, but the mountain-folk never caught sight of the Giant Goat.
Izek became a protector in the community over the span of months, as the most "civilized" barbarian in the tribe who could communicate with other Barovians. He lived as a wild-man for months until he encountered Mormeros Fayan, Ajuni Elajoral, and Tobias Villie Broadnose Cogsmith wandering the Tsolenka Pass. He had tried to cover himself in mud and bandage his arm, but was noticed by Mormmeros, who he felt an odd kinship with. Izek gave the group more details on Vallaki and Barovia, eventually welcoming them to Yester Hill should they venture westward.