Tristan

The Tristan is an eighth generation Knightmare Frame developed by the Holy Britannian Empire for the use of Gino Weinberg, the Knight of Three. Named after of the, it was heavily damaged during the attempted uprising of the Knights of the Round. It was later repaired and upgraded to the Tristan Divider.

Design and development
The Tristan is the first transformable Knightmare Frame developed and is able to tranform into a jet (Fortress Mode) in mid-air and utilizes a pair of machine guns. It has two massive Slash Harkens mounted on its forearms that are also equipped with Harken Boosers. The two Slash Harkens can combine to fire an every blast comparable to the Shen Hu's Baryon Cannon.

An eighth generation model, the Tristan, named after the Knight of the Round Table, is the first transforming Knightmare Frame ever developed, able to switch between humanoid (Frame) and jet (Fortress) forms. It is piloted by the Knight of Three, Gino Weinberg. It is highly maneuverable, able to fold out and transform in mid-air. It can utilize a pair of machine guns in its jet form. It has two massive Slash Harkens mounted on its forearms, which are equipped with Harken Boosters. The two Slash Harkens can combine to fire an energy blast, powerful enough to effectively match the Shenhu's Baryon Cannon. When in humanoid form, it can wield two pickaxe-like Maser Vibration Swords called the MVS Polearms, which can be joined together at the hilts to form a single, double-edged scythe. The Tristan is heavily damaged by the Lancelot Albion, during the attempted revolt against Emperor Lelouch.

Operational history
As a member of the Knights of the Round, ace pilot Gino Weinberg is granted his own R&D team, which constructs for him a customized personal Knightmare Frame. This machine, named the RZA-3F9 Tristan, is designed specifically to suit Gino's fighting style and personal preferences. The Tristan is a high-mobility model Knightmare, specializing in hit-and-run tactics using its slash harkens and wide-bladed MVS spears to cut through enemies quickly and cleanly. Already agile normally, the Tristan possesses the ability to transform into Fortress mode, making it a streamlined fighter for high-speed attacks. Gino makes good use of his Tristan until outcast Britannian prince Lelouch Lamperouge, formerly the terrorist Zero, claims the Britannian throne and leads the superpower towards his own ends. Siding with those loyal to the late Emperor Charles, Gino attempts to capture Lelouch, but is defeated in single combat with Lelouch's personal Knight, Suzaku Kururugi, and his Knightmare Frame Z-01Z Lancelot Albion. The Tristan, damaged, but still functioning, is upgraded by the Black Knights into a new form, the RZA-3F9X1 Tristan Divider.

Knightmare of Nunnally
In the manga spin-off Code Geass: Nightmare of Nunnally, Anya Alstreim uses a modified version of the Tristan. It is similar in appearance to the regular Tristan except for the Geass sigil on the Knightmare's face. It makes its first appearance in chapter 18 to fight the Lancelot. Its main difference to the original Tristan is its weaponry, being six Automated Trajectory Variable Type MVS Slash Harkens.