Kizaki uses Spider to lay trap by connecting it to a Meteora cube to create an explosive trap. Even if the enemy notices the traps, they will still be wary of moving in the area with wires, allowing Kizaki to control their position. Viza theorized that he uses the more obvious traps as bait for undetectable ones. He is capable of setting multiple of them while trading shots with an opponent without them noticing.
Kitora is one of the few Spider users in Border. She fires it through a customized gun, which has a reel-in function that allows her to use it much like a self-winding grappling hook to reach normally impossible heights. With it, she can move very quickly in a straight line even after the loss of a leg. She can set wires around herself to hinder an enemy's movements, although she claimed that traps of that kind will hardly work in one-on-one confrontations unless the conditions are perfect. However, weaving a Spider web around herself and her opponent permits her to limit their movements while at the same time increasing agility: by using the wires as footholds, she can circle around the enemy at high speed, looking for openings and attacking at once. Alternatively, she can fire Spider directly at the opponent, anchoring them to the closest surface and leaving them vulnerable to further attacks. She also has knowledge about several other possible uses of this Trigger.
Due to the low trion consumption of this Trigger, its versatility in the hands of a good strategist, and the low amount of skill, practice and accuracy necessary to use it, Osamu regards Spider as a near perfect weapon for him. His primary tactic consists in setting countless wires between buildings (or other structures) in wide areas of the map. Since the wires' color can be adjusted to make it very hard for enemies to spot, those areas become as disadvantageous to the enemy as they are advantageous to his unit. In fact, this application of the Trigger makes full use of his teammates' abilities, boosting Yūma's agility while relying on Chika's Lead Bullet sniping to prevent the wires from being cut down. They can also force enemies into the wire zones by having her shoot down other buildings with Ibis. The wire zones are beneficial to Osamu himself as well, enabling him to slow down whole units with minimal assistance from Chika. Since the opponent is hindered by the wires and must constantly watch out for them, whereas he can devote his undivided attention to combat alone, Osamu can score points on his own, and since the wires will keep supporting his allies even if he should bail out, he can fight without hesitation. As a matter of fact, Spider allows him to be useful to his team without fighting at all. An application of Spider that was not suggested to him by Ai Kitora is the creation of highly visible wires, which are generally red in color, and the gradation of the others: by summoning red wires when the enemies come too close, they will inevitably be less alert to the ones around them. This technique is more complex than it seems at first glance, because some of the normal wires are set to be more visible than others, which further disorients the enemy and prevents them from understanding why they tripped despite being careful. However, it will fail if there aren't enough wires in Osamu's vicinity. He can also anchor an enemy to an object by shooting the hooks directly at them, restraining them briefly. Osamu starts training with Spider in chapter 122, and uses it first in chapter 138.