Paladin Tristan

 is a Paladin of the Capital Wasteland Brotherhood of Steel who is added to Fallout 3 in the add-on Broken Steel in the year 2277.

Effects of player actions
He is the acting field commander of the Brotherhood forces in light of Sarah Lyons being down for the count, and is in charge of a Brotherhood operation involving the player and Liberty Prime, the first mission in the main Broken Steel questline.

Quotes

 * "Well well, look who's back amongst the living."
 * "Basic rule of thumb on these operations; keep your head down and let the robot do most of the heavy lifting."

Appearances
appears only in the Fallout 3 add-on Broken Steel.