Cassar is a character in the television series Mortal Kombat: Conquest played by Dean Cochran that made his appearance in Episode 11: Thicker Than Blood.
When his older brother was engaged to a woman named Hanna, Cassar showed deep feelings for her and Hanna developed such feelings for him as well and they fell in love. Siro felt that he was betrayed by them and started to fight his own brother, even almost killed before he disappeared. They never saw, nor heard from each other again.
One day, a mysterious woman approached Taja looking for Siro. When this woman who is revealed to be Hanna, told Taja that she once almost married Siro, Taja was stunned and intrigued. Hanna turned out to be married to Siro's brother, Cassar. She had come to Siro because Cassar was missing and she feared that he was in trouble. Siro, who was dumped by Hanna years ago, was ambivalent toward her plight and told her she was on her own.
Meanwhile, Scorpion reported to Shao Kahn his plans to raise a dark army in the Earthrealm. He was recruiting only the deadliest fighters to carry out his plans. Unfortunately, Cassar had fallen under the spell of Scorpion and had joined him in his quest.
Cassar and another of Scorpion's warriors went to the trading post to recruit Hanna to join them. When she resisted, a fight broke out and Cassar escaped, but the other warrior was captured by the Great Kung Lao, Siro and Taja. With a little persuasion and a big dagger, Siro and Kung Lao "convinced" the captured warrior to tell them where Scorpion was headquartered.
Since they would be outnumbered by Scorpion's warriors, Hanna devises a plan to infiltrate Scorpion's group in order to get Cassar back, pledging her loyalty to the cause as her husband had. Once she got Cassar alone, Hanna led him into a trap set by Siro and they took him back to the trading post where they work to "deprogram" him.
Cassar and Siro attempted to sort through years of sibling rivalry, which was fueled by their father who always made them compete with one another. Finally, Kung Lao, Taja, Hanna and Siro were able to convince Cassar to stay and join them in their noble quest.
Following a celebratory feast, Siro and Cassar were at the trading post, catching up on the years they'd been separated. Scorpion appeared and said he had come to reclaim what was his, meaning Cassar.
For the first time in their lives, the brothers fought alongside each other, instead of against each other. Scorpion, seething from Cassar's betrayal, had only one goal: to kill Cassar, something he achieved before vanishing into the night. As Kung Lao and Taja who were walking with Hanna, chased after Scorpion while she stayed behind with Siro and Cassar. As Cassar suffers Scorpion's crushing blow to his chest before he died, his last words were of mentoning Peron & "Take care of her, brother.".