Karl Schäfer is a character that appears in Uncharted 2: Among Thieves. He was a German expeditioner who was once a treasure hunter like Nathan Drake. He had once been told to find the entrance to Shambhala, but he decided to not continue his Ahnenerbe expedition after discovering the power of the Cintamani Stone.
Karl Schäfer is first met by Nathan Drake after Tenzin rescued him from the train wreck. Elena Fisher is with Schäfer in the village and introduces Nate to Karl. Tenzin and Nate then head up to an old ice temple hidden within an icy cave system. Nate notices all of the dead men littered through the cave and learned eventually that they were once Schäfer's expedition, that he had to kill. Nate then explains to Tenzin that the men were Nazis, and Tenzin showed that he knew full well of such men.. After leaving the ice cave and killing his expedition, Schäfer took refuge at the Tibetan village.
"You were right - everything you touch does turn to shit."
— Shafer shortly before death.
After exiting the cave, Nate and Tenzin notice the village is on fire due to Zoran Lazarević soldiers. The two explorers return to the village. Once arriving at the village, Nate and Tenzin visit Schäfer's house and notice it's empty. Zoran Lazarević's soldiers are attacking Tibetan fighters and Nate. After taking out the village invaders, Nate and Tenzin realize that Karl Schäfer was taken into captivity by Zoran. After saving the village, Tenzin thanks him and wishes best of luck to Nathan. Tenzin is last seen at Schafer's funeral. Elena and Nathan kill a soldier and jump into a convoy truck and follow Lazarevic's convoy. After the two arrive at the monastery they begin following Lazarević's trail up to an old tower.
After climbing and being attacked by soldiers, Elena and Nate find a bridge which they can cross to reach the other side of the monastery. The bridge collapses and nearly kills both Nate and Elena. After the two progress further through the monastery grounds, they notice a tower, in which they climb up. Inside they are attacked by Zoran Lazarević's soldiers and engage in battle. Elena and Nate open a door only to find Karl Schäfer barely alive. Karl speaks a few motivating words to Nate and tells him to move on and to stop Lazarević, also to destroy the Cintamani Stone. He then falls over dead, likely from being beaten and the rough ride. Nate and Elena then press on to find the Serbian war criminal and stop him.
The character Karl Schäfer is a likely reference to Ernst Schäfer, who led a real life expedition to Tibet in 1938. Like the character of Karl Schäfer, the real life Ernst wanted to find Shangri-La, and the supposed "Master Race" of people that inhabited the fabled land. As referenced in the game, the real life Schäfer had ties to Himmler's Ahnenerbe (SS) organization, although it is stated that he only joined in order to further advance his career in Zoology.
In the Uncharted 2 multiplayer you can play as Karl Schafer. The skin can be purchased $1,000,000 and you must be a level 50 to purchase him.
In Chapter 16 (Where Am I?), while explaining his expedition to Drake, Schäfer briefly takes out a Photo Album and just as quickly puts it away. If the player has time to catch it, the photos of (who is believed to be) a Younger Schafer bear a striking resemblance to Drake.
Schäfer is one of the only three characters in Uncharted 2 besides Nathan Drake to speak in foreign languages, along with Tenzin and Elena Fisher, who can speak Tibetan (Drake learns Tibetan sometime during Elena's recovery period). This is evidenced by Schäfer occasionally muttering "scheisse!" (German for "shit!") when shot, and his ability to speak to Tenzin in Tenzin's native tongue during the campaign.