Hound

"Guided bullets that pursue their target: Hound."

- Shiori Usami about Hound.

is a Gunner Trigger. Its properties change slightly depending on whether it is set to Detection Guidance (探知誘導) or Visual Guidance (視線誘導).

Appearance
Hound leaves a luminous trail in its wake, and it can be recognized by the way it curves to home in on the target. While traveling in a straight line, it is indistinguishable from other Gunner Triggers. Kako's customized version is manifested as a sphere, and it spawns smaller orbs of various size.

Overview
The origins of this Trigger are unknown. It was initially used exclusively in trion cube form, until firearms were invented. At some point, Kako had her model customized.

Abilities
Hound is one of the mid-ranged options available to Border agents, which can be fired as a trion cube or through a firearm. It is slightly less powerful than Asteroid, as part of the trion allocated to the bullet is spent on its signature ability to pursue the target. This special function, which is disabled at higher muzzle velocity, has two modes: Detection Guidance, which causes the bullets to home in on trion bodies, and Visual Guidance, which follows the user's line of sight. The latter is more precise, whereas the former is more effective against elusive opponents, such as Chameleon users and highly mobile targets. The mode can be changed after the trion cube is summoned and divided, before the fragments are fired.

Regardless of the mode, Hound's homing propensity, the degree to which the bullet is able to alter its trajectory to curve towards the target, can be adjusted freely. With a homing setting of 0%, the bullets will move in a straight line, whereas at 100% all bullets are likely to hit the same spot and can thus be blocked with a small Shield. The homing propensity is not homogenous for the entirety of the flight path of the bullet: regardless of its settings, as soon as the bullet is fired it will have 0% homing propensity, subsequently growing until it reaches its peak, after which it gradually falls again, seemingly without ever reaching zero. For this Trigger to be utilized to its full potential, homing propensity must be adapted to the context and bullets from one same volley may be given different homing settings to make them more difficult to block or dodge. Nonetheless, it appears that, regardless of their homing propensity, Hound bullets can be avoided by luring them in one direction and sharply reversing course. As seen with Chika Amatori, if combined with Lead Bullet, Hound bullets become exponentially harder to defend against, as the issues with homing propensity become less of an issue with the optional trigger's advantage of bypassing shields altogether.

Hound is frequently used to create a diversion, pressure the opponent, or force them to move, but it has a variety of other applications. Bombarding an area from afar can whittle down an opponent's defenses, while disguising this Trigger as Asteroid may lull the target into a false sense of security after they move away from its initial trajectory. A spread-out volley can force them to widen their Shield, making it more vulnerable to subsequent focused attacks. It is possible to catch the opponent in a pincer by firing a second volley in a different direction, by launching a frontal attack with another projectile, whether with a Gunner Trigger from the opposite column in the user's Trigger Set or, by exploiting the delay, with another one from the same column. The pincer attack can be even carried out with the fragments of a single trion cube by angling them in opposite directions or by giving them different homing settings. Hound bullets fired outside of the target's line of sight may hit them from a blind spot. Particularly skilled users can angle the bullets and adjust the homing propensity so as to circumvent the target's defenses. Most applications of Hound require an abundance of unencumbered space, so it is most effective outdoors, where being surrounded by multiple opponents equipped with this Trigger is known to be especially dangerous.

As a Gunner Trigger, Hound is less powerful than Attacker Triggers in normal circumstances and consumes more trion than the latter. The higher the trion amount of the user, the more of it can be allocated to its three basic parameters, enhancing its performance. A safety mechanism is in place so that, should a bullet collide with a flesh and blood body, the owner will be knocked out from the pain and impact, without suffering any penetrating trauma.

Customization
Aside from its unique shape and division method, any additional abilities possessed by the customized Hound used by Kako are still unknown. Some of the orbs appear to be bigger than the others, which could mean that trion can be divided unevenly among them.

Users
See also: Hound Users

There are 26 known agents with at least one Hound chip in their Trigger Set including Nozomi Kako's customized variant, which makes it the second most popular Gunner Trigger. Among these agents, 14 fire it in the form of a trion cube, nine through an assault rifle, and four through one or more handguns, with Sumiharu Inukai being notable for using Hound as both a Gunner and a Shooter. No. 1 Shooter Masataka Ninomiya is regarded as an expert, while Chika Amatori is feared for her unique ability to effectively combine it with Lead Bullet as well as for her sheer firepower, which would make a volley with 100% homing propensity extremely difficult both to block and to avoid.

Hound is also used by an unknown number of trainees, and possibly by agents who do not take part in rank wars. Among the former, Teruteru Kōda and Fumifumi Saotome are worthy of note.

Trivia

 * The author stated that the two different sets of kanji used in the Trigger's name were supposed to reflect which mode is in use: "誘導弾" ("guided bullet") when set to Detection Guidance, "追尾弾" ("tracking bullet") when set to Visual Guidance. However, he admitted to making many mistakes with the nomenclature.
 * Like many other Gunner Triggers, Hound is named after a missile: possibly the AGM-28 Hound Dog or the Bloodhound.
 * A hound is a dog whose main purpose is to aid hunters by tracking prey by scent, similar to how this Trigger tracks and follows an opponent.
 * Noboru Koarai expressed interest in adding Hound to his Trigger Set, and he is known to have subsequently equipped a Gunner Trigger. If that bullet is Hound, he would be the 27th among official agents who take part in rank wars.