The Guren Mk-II (紅蓮弐式, Guren Nishiki?, lit. 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. In keeping with its name, the Guren's armor is predominantly red. 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 Stadtfeld.
The Guren Mk-II's main weapon is its right arm. The arm is silver from the elbow down, and terminates in clawed fingers. Stored within the palm is the radiant wave surger (輻射波動, fukushahadō?, lit. radiation surge), a powerful microwave radiation emitter. By grabbing onto an enemy Knightmare 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. The arm can unhinge at the elbow to extend the Guren's reach. 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 Guren Mk-II also possesses a fork-shaped knife, a grenade launcher on its left arm, and a single Slash Harken.
In the second season, 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 (紅蓮可翔式, Guren Kashōshiki?, lit. 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, as well as a new "armor-piercing bombardment-type" radiant wave surger arm. The new arm has a dark gray forearm with silver fingers. 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 Asplund is given access to the Guren. Much as Rakshata had done when creating the Shen Hu, Lloyd and Cécile Croomy got carried away in their modifications, which resulted in a machine that they believed no one was capable of piloting. In his care, it is upgraded into the Guren S.E.I.T.E.N. Eight Elements (紅蓮聖天八極式, Guren Seiten Hakkyokushiki?, lit. Crimson Lotus S.E.I.T.E.N. Eight Elements-Type). S.E.I.T.E.N. stands for Superlative Extruder Interlocked Technology Exclusive Nexus. At this stage it is arguably the most powerful Knightmare frame in the series contested only by the Lancelot Albion. Kallen states that the Guren has better specs than the Lancelot in the final episode, hinting that the Guren may indeed be stronger. For flight, it uses a four-feathered Energy Wing designed by Cécile. The system allows the Guren to move at blinding speeds, such that it appears to be little more than a pink blur in flight. The wings can also serve as cutting weapons. Additional armor is added on the legs and left arm, replacing the cannon, 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 single chest-mounted Slash Harken is also gone, replaced by a pair of larger Slash Harkens mounted in its shoulder joints. Its radiant wave surger arm has also 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 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. Its MVS (which is colored purple as opposed to the usual red) is evidently more potent than normal versions, as it can cut through the Lancelot Conquista's MVS swords. It is damaged in battle against the Lancelot Albion, losing its head and both arms, but the chest survives intact. Artwork from the Last Picture Drama shows the Guren S.E.I.T.E.N rebuilt for reasons unknown.
In the Nintendo DS version of the series, Kallen also received an upgraded version of her Guren, the "Guren Mk-II Kai". This version is a slightly heavier version of the Guren Mk-II and has a black color scheme instead of Red. While it resembles the original Mk-II, the radiant wave surge is however covered in full armour, making it much larger than normal, and has four fingers instead of five. It also have a fork knife attached to its left arm.
Read more about this topic: Knightmare Frame, Japanese Models