Role in the book Edit
Like the other Tarids, Ul Vas has the ability to render himself invisible to others with the help of a hypnotic spell. Thus, when John Carter, Dejah Thoris, Jat Or, Zanda, Ur Jan and Gar Nal are taken captive upon arrivin on Thuria, they cannot see him. When Carter learns how to resist the hypnotic spell from Umka, he sees that Ul Vas is a fat and old man. Ul Vas has little interest in his captives and decides to sacrifice them all to the fire god (the sun). However, all Barsoomians manage to escape from his castle before he has a chance to do so.
At some point prior to the story, he has abducted a woman named Ozara from the city of Domnia in order for her to be his wife. Ozara hated Ul Vas but didn't dare try to escape. Seeing an opportunity to escape, Ozara plead John Carter for his help. Carter agrees and helps her escape as well. After his prisoners escape, Ul Vas is not seen again.
Other apperances Edit
|The information in this article comes from John Carter: Warlord of Mars and is not written by Edgar Rice Burroughs.|
In the story, the Morgors invade Barsoom and quickly capture Helium. John Carter and Dejah Thoris are also captured, but freed by Vorion. Knowing the Morgors will no doubt attack Thuria as well and deducing that the enemy of his enemy is his friend, Carter suggests they go to Ul Vas and ask for his help. When they arrive in his palace, it is revealed that Ul Vas has abducted a new woman to be his wife. He is still angry at John Carter for having taken Ozara away from him, but after John Carter and Vorion take him on a trip on Vorion’s ship and show him the Morgor invasion, he agrees to assist Carter in defeating this mutual enemy. To do this, Ul Vas contacts Bandolian, pretending to have captured Vorion, John Carter, and the Morgor Rebels. He delivers them to Bandolian on his ship as a peace offer in return for Bandolians promise that Thuria will be left alone. In reality however, this is a trick to smuggle a large group of Tarid soldiers, under the guise of their invisibility, onto the Imperial ship and capture all the Morgors there. The plan succeeds, and in the proces John Carter kills Bandolian. Afterwards Ul Vas returns to Thuria.