Commandant Steele

"You have failed to listen to Commandant Steele."

- Steele to the Vault Hunters "The contents of the Vault are rightfully the property of the ATLAS corporation but you....you belong to me."

- Steele before opening the Vault Commandant Steele is an officer in the Crimson Lance and the primary antagonist of Borderlands. She is a siren and thee leader of the Crimson Lance forces on Pandora, determined to open the Vault.

In the game
Commandant Steele leads the Crimson Lance army, the lawless fighters encountered in Old Haven and beyond. She claims the alien technology she believes to be hidden in the Vault as the property of the Atlas corporation and tries to take the vault keys by force after the last piece is collected.

After the Vault Hunters kill Baron Flynt, believing that he has the last peace of the Vault key, they are contacted by Steele who reveals that Flynt has no part of the key. While the Vault Hunters were busy, her forces captured Patricia Tannis and took the Vault key from her. Having everything she needs to open the Vault, Steele and her forces move to the Vault, ready to open it. To stop the Vault Hunters she sends the Crimson Lance to attack and shuts down the ECHOnet. Just before the ECHOnet gets shut down it becomes clear that she is making a stronger bid for power than originally expected when Crimson Lance forces under her control are reported to be assaulting Sanctuary. Shortly thereafter, she is briefly seen setting up a trap for the Vault Hunters, ordering Master McCloud to execute them. When the Vault Hunters follow her, they encounter her at the Vault. She tells the Hunters that they have come too late and uses the key, awaiting treasure. In truth, the Vault contains the Destroyer, who impales Steele on one of his spikes while she gives her victory speech, before fighting the Vault Hunters.

Claptrap's New Robot Revolution
In the forth DLC she is revived as Commandant Steele-Trap. After the destruction of the Destroyer, she finds herself suddenly awake in an unfamiliar place, and in her attempt to complete her victory speech also finds herself conflicted by new directives to fight for the glory of Claptraps everywhere. More shocking still is the discovery of a gaping hole where her abdomen used to be and the Vault hunters standing before her once again. With instructions to kill the intruders, and those same intruders having been a thorn in her side for far too long, she attacks but is killed, this time for good.

Trivia

 * Despite being the main antagonist, she has few appearances in the game and is never fought directly