Spider

"The good thing about this Trigger is that it doesn't use much trion. You can adjust the color of the wire so it'll be harder to spot. You work with the Operator for visual support, and make it so only your allies will see the wires clearly."

- Ai Kitora about Spider

Spider (スパイダー) is an Optional Trigger. Ai Kitora's customized version, however, is classified as a Gunner Trigger.

Appearance
When activated, Spider takes the form of a small trion cube with two arrow-shaped hooks in the middle of opposite edges. "Firing" the cube causes it to vanish and shoot the hooks in the direction they were facing, connecting them with a moderately thick wire. The wire is gray, but its color can be modified at will. Kitora's Spider is integrated into her gun, which has an opening under the main barrel to shoot Spider from.

Overview
The origins of this Trigger are unknown, but it is known to have been developed since before Mirai Hatohara's defection.

Abilities
Spider creates wires that can be used to trip opponents and obstruct their movements. In most cases, vertical structures are required to set the wires. By shooting one hook into the enemy and one into an object, it is possible to restrain them momentarily. Multiple Spider cubes can be conjured and fired at the same time, their number being dependant upon the user's trion reserves. The wires can be cut or broken very easily, but since this Trigger consumes a small amount of trion, it is possible to set a great many of them. By working in conjunction with an Operator, the color of the wires can be modified so only the user's team members will be able to see them clearly, making certain areas of the map favorable only for the user and their allies. Those with sufficient trion can combine Spider with Meteor to create tripwire explosive traps.

Spider's usefulness as a way to score points is very limited since opponents will be able to spot the wires if they look closely, and prolonged exposure will allow their eyes to adjust. The user can counter this gradual adaptation by mixing highly visible and nearly invisible wires, a tactic that can be rendered more effective by adding gradations between those extremes. However, it will fail if there are few wires in the area, and the visible ones can be exploited by sufficiently skilled enemies.

Nonetheless, Spider has great value as a deterrent and supporting Trigger. In fact, if the enemy can see the wires, they will hesitate, suspecting a trap, and their attention will be diverted. On the other hand, nimble combatants on the user's side can make use of the wires to further increase their agility. The capacity to change direction in mid-air renders their movements unpredictable and, with sufficient practice, their speed prevents even opponents well acquainted with their fighting style to follow them at close range. Since the existence of the wires is independent of the Trigger user, they can keep supporting their allies even after bailing out. This makes Spider a particularly good pick for fighters with low combat abilities and accuracy.

Due to its fragility, Spider is particularly vulnerable to Triggers with a wide area of attacks such as Meteor and Senkū, as a single-use can tear down all the buildings and wires within range. For the formation to be effective, it is thus necessary for a long-range combatant, especially a Sniper, to be inside the web and shoot back as soon as the line of sight is cleared, deterring the opponents from cutting down more wires, which in turn permits the user's allies to retain their geographical advantage.

Thanks to the customization of her gun, on top of setting the wires in the environment to increase her speed and agility, Kitora can fire Spider directly at the opponent to restrain them long enough to deal a critical strike. The built-in reel-in function allows her to reach otherwise inaccessible heights as well as to move very quickly in a straight line despite the loss of a leg.

Users
Spider was noted to be an unpopular Trigger due to not directly leading to the scoring of points. As a matter of fact, it has only 5 known users: Reiji Kizaki, Takaaki Katagiri, Osamu Mikumo, Yōko Katori, and Ai Kitora, the latter of whom utilizes a customized version. Mirai Hatohara is a former user.