Kallen is a Britannian-Eleven girl, who believes herself to be a Japanese person at heart and prefers to be known by her birth name, Kōzuki. Her father is Britannian and her mother is an Eleven; her father comes from a prestigious Britannian family, which Kallen benefits from. She attends the Ashford Academy, where she is a member of its student council and is one of its most outstanding students. Her brother, Naoto Kōzuki, with whom she had a deep connection, was a former leader of her resistance cell before his death. Both Kallen's stepmother, a Britannian, and biological mother live with her in the same house, but her biological mother is employed as a maid and is often mistreated by both her stepmother and Kallen herself. After her biological mother is arrested for using Refrain (a fictional drug which lets people think they're reliving the past), Kallen changes her views and decides to fight against the Britannian Empire not only for her brother, but to fulfill her new wish for a world in which she can live happily with her biological mother.
Gurren Mk II
The Gurren Mk-II (
Crimson Lotus Type-02) is a unique Knightmare Frame model designed by Indian engineer Rakshata Chawla, manufactured by Japan, and built by the Kyōto House. It is radically different from its Britannian counterparts, and its technology is on par with seventh generation Knightmare Frames, such as the Lancelot. The Guren Mk-II's speed and strength can easily match the Lancelot's, but its lack of long-range weapons relegate it to a defensive close-combat role. Unlike Britannian-made Knightmare cockpits, the Guren Mk-II features an unconventional pilot seat, shaped like a motorbike, and a helm-like outgrowth surrounding its retractable head. Its Landspinners fold out from within its legs instead of being attached to the ankle. It is given to the Order of the Black Knights and piloted by Kallen Kōzuki.
The Guren Mk-II's main weapon is its silver right arm. The arm stands out from the otherwise red-painted mech, terminating in clawed fingers, and it can unhinge at the elbow for a surprise attack. Stored within the palm is the radiant wave surger ( radiation surge), a powerful microwave radiation emitter. By grabbing onto an enemy Knightmare Frame and activating the emitter, the Guren Mk-II can fry the enemy's electronics and warp the frame itself, causing it to explode after a brief pause. The warping effect can also fuse the cockpit to the frame, preventing ejection. While not designed as such, the radiant wave surger can also function as a shield capable of blocking almost any attack, only failing against the Lancelot Conquista's Hadron Blaster. The arm is destroyed in the first season by Suzaku Kururugi, but is replaced in the second season with a slimmer, three-fingered version. The new arm is again destroyed by Suzaku. The Guren Mk-II also possesses a fork-shaped knife, a cannon on its left arm, and a single Slash Harken.
After being badly damaged in battle by Suzaku's Lancelot Conquista, the Guren Mk-II receives a mid-battle upgrade through a series of rocket-mounted attachments. The upgraded model is dubbed the Guren Flight-Enabled Version (Crimson Lotus Aerial-Type). It gains an integrated Float System and antenna on the sides of its head which carry a radiant wave surger-based shield. A new "armor-piercing bombardment-type" radiant wave surger arm replaces the old one. This new arm matches the Knightmare's color scheme, though the forearm is dark gray and the fingers are still silver. In addition to its close-range blast, the new radiant wave surger arm can also fire a concentrated long-range beam or a wide-range blast. The long-range beam can eliminate multiple targets in a single shot. The wide-range blast, though not as destructive, cripples any Knightmares caught in it, and can still destroy weaker craft such as helicopters. Another addition to Guren's arsenal is the 'Gefjun Net', a series of small, fast-moving drones launched from the back of the Guren that surround an enemy Knightmare and release a Gefjun Disturber surge, immobilizing it.
After Kallen and the Guren are captured during a battle with the Chinese Federation and turned over to Britannia, Lloyd is given access to the Guren Mk-II. Much like Rakshata and the Shenhu, Lloyd and Cécile got carried away in their modifications and made it too difficult for ordinary people to pilot properly. In his care, it is upgraded into the Guren Seiten Eight Elements-Type (Crimson Lotus Seiten Eight Elements-Type). S.E.I.T.E.N. stands for Superlative Extruder Interlocked Technology Exclusive Nexus. It uses a wing-like Float System designed by Cécile that uses four energy feathers for flight. The system allows the Guren to move at blinding speeds, such that it appears to be little more than a purple blur in flight. Additional armor is added on the legs and left arm, and the antenna have been extended and enlarged, making them appear to be giant ears. The chest armor is extended into the shape of a beak and a pair of green jewels featured prominently on the front. Its radiant wave surger arm has been upgraded significantly. It can be fired like a Slash Harken, and has a Harken Booster for controlled flight. The arm still functions when launched as such. Its original functions are retained and far more potent: the ordinary radiation burst can block a Hadron Cannon blast with seemingly no effort and the hand can crush energy shielding without the aid of the emitter. In addition, it can fire energy disks. The Guren's fork knife is also upgraded, having been retrofitted with MVS capability and made about twice as long.