Tristan was assigned to Oskar Von Reuantal, one of the "Twin stars" of the Empire under the Lohengramm dynasty. Like the Beowulf it was a new design produced from the results of the Brunhild's innovations.
Unlike Beowulf, Tristan had a small-scale X-Ray beam cannon in the nose. Forward weaponry was reduced because of this.
After Reuantal's uprising and subsequent defeat, Tristan was moored at Heinessen while the Admiral awaited his best friend- and death- in his provincial headquarters. It is unclear what happened to Tristan following the admiral's death- weather it was repaired or not or even remained on Heinessen.
Sister ship to the Tristan and under the command of Wolfgang Mittermeyer- the "Gale Wolf" and other half of the 'twin Stars' of the Empire. Though Mittermeyer's skills and speed lend him to be deployed more often than Reuantal, Beowulf was in the line of fire nearly twice as often and received battle damage on several occasions.
Beowulf mounts six bow-mounted cannons in the nose, strengthening its forward battery. Like Tristan, Beowulf also benefited from the reflecting hull structure pioneered by the Brunhild and so has a higher defense in the bow.
Decided to re-do both of these warships, after discovering a high-detail sketch of the Tristan. Didn't really like my first pass on the twin stars, so here's a little more justifiable of a portrayal.