Rundas is a bounty hunter in the video game Metroid Prime 3: Corruption for the Wii. Unlike most bounty hunters whom are against Samus Aran, this one helps her for the most part of the beginning of the game. Once Samus is surrounded by four Space Pirate ships, Rundas comes to the rescue and freezes them all. He later saves her again from falling down a pit after defeating Ridley.
After losing contact with the Galactic Federation, Samus is asked (or rather commanded) to go and find him. He was reported to have landed on the planet Bryyo. So she sets off to go to the planet to not only rescue or at least investigate what's going on with Rundas, but also to obliterate the seed that's been infecting the planet with phazon. Eventually she spots him, though she soon discovers that he's been deeply corrupted by Dark Samus, and doesn't hesitate to fight him. At the end of the battle, Rundas gets stabbed by his own ice spear, thus killing him.
This is also the result of the other two warriors who were helping Samus, who also die at the hands of the bounty hunter.
Once Rundas is defeated, Samus will obtain the Ice Missiles (hence Rundas deals with ice). Ice Missiles are an upgrade in regular missiles, and are able to freeze Fuel Gel (for a short time), open white colored doors, and even freeze certain enemies.
Later on in the game when you're forced to fight Gandrayda, who has the ability to transform into other beings, one of her forms is Rundas (along with Ghor, a Space Pirate, a Berserker Lord, and even Samus) for a short time, where she'll perform the same attacks that he did in his boss fight.
Almost all of his abilities involve using ice. He can easily freeze enemies within a second, and can also soar in the air by gliding on his self-generated ice which seems to quickly melt. He also seems to be able to raise ice from out of the ground giving him platforms and even use them against his opponents.
Rundas is obviously not human, and despite looking robotic, he's not. He is known to be Phyrigisian, a type of people who can generate ice. Phyrigisians live on a moon, called Bes III, which is primarily used for ice mining by the Galactic Federation.