Xenia

Xenia is an old, veteran adventurer, first refered to in the Twitter hint of 14 March 2010. She was released along with the quest The Blood Pact and the Lumbridge Catacombs on 15 March 2010, the first Free-to-play quest to be released since 2003. Players must talk to Xenia to start the quest The Blood Pact, which involves escorting her into the Lumbridge Catacombs to fight three Zamorakian cultists, Reese, Kayle and Caitlin. Xenia herself claims to be one of the founding members of the Champions' Guild, and apparently has contacts within the Heroes Guild and Legends' Guild as well.

The Blood Pact
Xenia first meets the player during the quest The Blood Pact, which is started by talking to her. Xenia is waiting outside the entrance to the Lumbridge Catacombs, where she will ask the player for help with three Zamorakian Cultists which have kidnapped an apprentice at the Wizards' Tower, Ilona, in order to sacrifice her in the name of their god and raise an army of the undead to take over the town of Lumbridge. When fighting the first cultist, Kayle, Xenia feigns being injured in order to test the player in their combat skill. Once all the cultists have been defeated, Xenia and the player rescue Ilona, and the quest is completed.

Other Rewards from Xenia
After the quest, Xenia remains in Lumbridge Cemetery and can hand out additional rewards to the player. If Reese's Sword, Kayle's Shortbow or Caitlin's Staff are lost, they can be reobtained by talking to Xenia. If the player kills certain monsters in the Lumbridge Catacombs, they can take several Demon statuettes from the tombs and hand them to Xenia for coins of varying values, depending on how rare the gem in the statuette is.

If the player speaks to Xenia after the quest with 300 or over quest points, they can obtain the Helmet of trials, a decorative helmet worn by players to show off their prowess in questing, much like a skillcape. However, unlike the Quest Cape, the amount of quest points needed to wear the helmet will not fluctuate as more quests are released; it will stay at 300.

Trivia
Xenia
 * Xenia is also the name of the Greek concept of hospitality, or generosity and courtesy shown to those who are far from home.
 * Interestingly, Xenia shares a name with Merchant Xenia, a trader who plays a small part in The Chosen Commander, in which she sells "exotic" items and spices to Cave goblins in Dorgesh-Kaan.
 * When Xenia is shot by Kayle she takes merely 2 damage but appears to only have half of her life points left. This is because she was pretending it was worse than it was, as is revealed in dialogue with her after the quest.
 * Depending on how many quest points a player has, Xenia will respond to "How did you know my name?" in several different ways. If the player is a non-member and has not completed Dragon Slayer, Xenia will claim that she "heard you helped Sir Vant kill a Dragon in his Roddeck's cellar." If the player has completed Dragon Slayer, she will say that she heard through the Champions' Guild that the player slew Elvarg. If the player has completed the Legends' Quest, she will claim she heard of the player through her contacts in the Legends] Guild, and if the player has in excess of 291 quest points, she will say "You're a legend even in the Legends' Guild! It's a pleasure to meet you."
 * If you completed Demon Slayer, she will claim she heard of you.
 * If you talk to her, while wearing Dragith Nurn's Mask, she'll say that you're ridiculous.
 * She appears to be wearing what look a bit like Menaphite robes.