Stella only appears at the Fort once the Laurifer Gladiator quest is begun.
She has a number of special perks that increase her effectiveness in unarmed combat. In combat with the Courier, she can easily cripple limbs in one or two hits, making her a dangerous opponent.
Stella always appears in the arena, even if the Courier has not yet triggered the attack on Ranger station Charlie by either speaking with Ranger Andy in Novac or beginning Return to Sender.
Killing Stella does not lower the Courier's reputation with the NCR. However, some Legion soldiers at the Fort may be impressed and comment on her death.
↑The Courier: "I'd like to fight in the arena." Otho: "I have a dangerous one for you - an NCR Ranger by the name of Stella. We got lucky, since we rarely capture Rangers alive. Even though she's a woman, she's killed every man who's faced her in the arena, even one of the elite Centurions. With her bare hands." (Otho's dialogue)
