Ortyr

Background
Ortyr was a frost giant from the realm of Jotunheim. Before Ragnarok, he was a Diplomat for the Giant King, Laufey. He fathered two sons, Orgyr, and Modir, who then became soldiers in Laufeys army. But when the trickster god, Loki, and the giant Surtyr made a deal to destroy the asgardians and usurp the Jotunn throne, Ortyr stood in their way.

He and his sons stood at the bifrost in Jotunheim and waited for Loki and Surtyr. When they arrived, they brawled on the rainbrow bridge. In the end, Ortyr was left wounded and his sons were dead. He watched as Surtyr and Loki murdered Laufey and took the Jotunn throne.

Ortyr escaped Jotunheim, and retreated to Midgard.

Ragnarok
When Loki and Surtyr stormed Asgard, Ortyr assembled an army of Jotunn rebels, sympathetic to his cause of vengeance. The battle was fierce and many of the Aesir gods were killed. With the exception of the brothers, Magni, and Modi, as well as the watcher Heimdall.

Ortyr retreated back to Midgard. But Surtyr had followed close behind. Ortyr watched the giant burn his home and slaughter his friends.

The War Against Surtyr
Shortly after Ragnarok, Ortyr remarried and fathered a son, named Eymir. Ortyr lived in seclusion, hiding from Surtyr in Midgard. But when the Aesir god Modi offered Ortyr a seat in Asgard, he couldn't refuse. Ortyr took his family to the realm of Asgard where he aided in the rebuilding of Valhalla and the city.

But Magni created a plan to attack Surtyr's army in Muspelheim, and get revenge for the death of the Aesir gods. Ortyr was made general of the Jotunn forces in Asgard. Together, Magni, Modi, Heimdall, and Ortyr created the Aesir-Jotunn pact. The pact stated that Jotunheim and Asgard would remain allies, and Ortyr would rule as king of the Jotunn.

Magni and Ortyr took their armies into Midgard, to gain control over the realm. But Surtyr had already arrived with his army of fire giants. The Drugr king Ferfeffnir also arrived with his army of Draugr. A giant battle erupted in Midgard. And Surtyr was defeated. He retreated back to Muspelheim.

Ortyr was enraged, so he crossed the bifrost into Muspelheim where he dueled Surtyr. The duel was so fiersome and virulent, that a piece of Muspelheim broke awy and created the new realm of Askrheim. Surtyr was too strong, Ortyr knew that. Ortyr took his power and spirit and handed it off to his son Eymir, to succeed him, as king of Jotunheim.

Ortyr was killed by Surtyr. And the war became even more violent.