Yūma Kuga/Abilities

Despite his young age and even younger appearance, Yūma is an experienced warrior of rare skill. His father trained him for six years and, after his demise, Yūma continued fighting alongside Calvaria for three more years. Having received a Black Trigger from Yūgo, his combat prowess increased exponentially, which eventually led to Spinthir withdrawing its forces. Yūma's Black Trigger is even more effective in battle when Replica assists him in the overlapping and combination of seals and the creation of new ones, making both processes instantaneous. The Trion Warrior also helped Yūma continue his training in strategy after Yūgo's passing, and the loss of the need and ability to sleep gave Yūma even more time to spend on it.

After joining Border Yūma achieved a working command of many applications of the organization's Triggers in an extremely short amount of time and went on to hone them, eventually being praised not only for his proficiency, but also for his ability to utilize Trigger Set in completely novel and tremendously efficient ways. His fighting prowess is further augmented by the speed with which he can activate and change his Triggers, which allows him to instantly switch from attack to defense and back to offense and has prevented him from bailing out on countless occasions. Rapidly switching Triggers is also a component of his effectiveness at aerial combat, which in turn translates to Yūma possessing such high mobility that he can hold his own against whole enemy teams by quickly flitting in and out of range and turning their own teammates into obstacles for each other. Osamu’s deployment of Spider threads enhanced his effectiveness even further, making his movements even faster and harder to predict, to the point that entire units from the middle of B-Rank were at a severe disadvantage when confronting him inside a wire zone. Even without them, however, Yūma was able to keep track of the movements of the members of Miwa Unit and Azuma Unit, and later matched no. 6 Attacker Tatsuhito Ikoma in combat while he was assisted by Satoshi Mizukami. On those occasions he suffered notable injuries only when previously hidden Snipers attacked him, and even then he managed to mitigate the damage.

His fighting capabilities have led him to being extolled as worthy of A-Rank and put him on par with some of Border's most skilled Attackers. After Tamakoma Second's second Rank Battle, his mentor was surprised to find out that he had been beaten by someone other than Kei Tachikawa, Sōya Kazama and herself, that person being the no. 4 Attacker Kō Murakami. Yūma currently holds a victory ratio of 38.8% against Murakami and 47.6% against Masato Kageura, even though Murakami considers himself less powerful than Kageura and has more losses than wins against him. In addition, Yūma is the only member of the trio without a Side Effect to boost his performance in battle. Yōsuke Yoneya described his movements as "quiet, matter-of-fact and deadly", adding that their sole purpose is to take out the opponent as efficiently as possible. This no-frills style reflects Yūma's single-mindedness in combat, which allows him to fight without emotion and makes him one of the only two people in Border not to trigger Kageura's Side Effect. He was also noted to excel at landing fatal blows in the middle of chaos, a skill which aids him in launching sneak attacks.

Although swordsmanship is his specialty, Yūma has shown to be competent also at hand-to-hand combat while using his Black Trigger. He generally resorts to kicks to deal damage right after approaching an enemy and to relocate them, and to punches when he is more confident that he will be able to land a decisive blow. Additionally, he has exhibited some skill with projectiles through his Bolt seal, hitting a very distant target with Replica’s guidance.

Possibly owing to his many years on the battlefield, Yūma was able to tell that Jin was powerful at a glance, admitting that he could not determine if he would be able to defeat him even with Replica's assistance. He also assured Osamu that he would die if he fought a Mole Mod, since 20 copies of him would be needed to take one down, and only two of them would survive. His years of traveling with his father endowed him with extensive knowledge of the Neighborhood and Trion Warriors as well as of how to defeat them.

Physical Abilities
Yūma’s agility and movement speed constitute the very core of his fighting style and allow him to fight on par with several Border agents at the same time, as epitomized by his confrontation with Miwa Unit. He can run on walls and bounce off vertical surfaces to change his trajectory or gain momentum with ease and control his body in mid-air with shocking accuracy. His swiftness is further increased by his Bound seal and Grasshopper as well as Osamu’s Spider wires. Combined with the latter, his movements became even more difficult to read. Being light he can move more precisely in aerial combat than bulkier opponents, and his small frame makes him even harder to hit.

Yūma’s reactions are extraordinarily quick, allowing him to block Asteroid bullets at point-blank range both in his normal and in his combat trion body. He can also block or dodge Eaglet and even Lightning shots, or at least move out of the way enough to avoid fatal damage, even if they are fired by two of the very best Snipers in Border, Azuma, and Narasaka. Combined with good spatial awareness, his fast reactions aid him in melee as well, as shown when he managed to dodge the coordinated attacks of two A-Rank agents while refraining from retaliating. Later on, he was able to fight off three B-Rank agents at the same time with the help of Osamu's Spider wires and twice without, although on the latter two occasions he lost an arm.

Strategy & Tactics
Yūma is proficient at reading the flow of battles small and large and to adapt to changing circumstances. However, he always leaves the command of their unit and the planning of the greater picture to Osamu, focusing exclusively on his own fights and how to best defeat his opponents after they start. His skill at breaking down their fighting style has allowed him to neutralize Miwa Unit with relatively pacific methods that forced him to remain on the defensive for a long time. It is through clever tactics created on the spot that he was able to defeat Tetsuji Arafune, Akane Hiura, Kazuaki Ōji, and, with Hyuse’s help, no. 4 Attacker Murakami. The only other time the two fought in a team battle Yūma beat him via previous planning, by forcing him to fight in conditions favorable only to himself. The single most remarkable feat which Yūma’s skill at improvisation analytical and tactical prowess, together with the unique abilities of his Black Trigger, allowed him to achieve, however, is his victory over the incredibly powerful and experienced Viza despite the loss of Replica's support, although the Aftokrator soldier's primary aim was to stall him.

Yūma is also adept at psychological manipulation, pretending to be at a disadvantage in a confrontation in order to cause his opponent to underestimate him, and thus to lower their guard while at the same time reducing the sharpness of their movements when they find themselves unable to land a decisive blow. With this method, he inflicted a crushing defeat on A-Rank agent Shun Midorikawa on the day of his enlistment.

Track Record
The first time Yūma wielded a Border Trigger, he won 1 round against the extremely powerful and skilled Kirie Konami after losing 9. Even when he grew more accustomed to them he never managed to get more than 3 wins against her, which Kyōsuke Karasuma regards as a feat in itself. On the day of his enlistment he broke every record for the simulation against the Bamster by clearing it first in 0.6 seconds and then in 0.4. No. 2 Attacker Sōya Kazama estimated Yūma to be already at Master Class level or higher, an assessment which was proven correct when the Neighbor defeated A-Rank Attacker Midorikawa shortly afterward with a score of 8 to 2 while wielding a training Trigger, although part of the merit goes to his psychological warfare and Yūma himself admitted that he would have struggled if it had not been for his matches against Konami. At the time Midorikawa did not use his full loadout to better see the gap in their swordsmanship, but in subsequent matches where both could use their full Trigger Set Yūma always won 7-3.

Yūma's defeats at Murakami's hands are partly due to the latter's Side Effect: when the two fought for the first time, the score changed from 4-1 in the Neighbor's favor to 6-4 for Murakami after the latter had a chance to assimilate his opponent's fighting style, although Yūma might have been holding back. The next time they fought, an injured Yūma turned the tables on Murakami thanks to his ingenuity despite the no. 4 Attacker being estimated by Yūichi Jin to be four times more likely to win. Currently Yūma has become capable of holding his own against Murakami despite the latter having learned his movements, although he still holds more losses than wins, and is almost evenly matched with Kageura. His 20-round match with Hyuse right after the latter created his Trigger Set resulted in Yūma winning 12 times and losing 8.

Side Effect
Lie Detector: After receiving a Black Trigger from his father, Yūma also gained his father's Side Effect of being able to distinguish lies from truth. It is not limited to lies alone, as it can also recognize omissions of detail and half-truths. It activates automatically when someone Yūma is looking at lies. When he uses this ability, his pupils become black. Apparently, Yūma can see through even Replica's lies, shown when he says it's uncommon for Replica to lie after he asks how Osamu and Chika are and Replica says there's no need to worry. However, Yūma's pupils don't become black, so it's possible he simply can tell when Replica is lying.

Trion Body
Yūma is always in a special trion body due to his real body being sealed in his ring to prevent his death. This grants Yūma enhanced physical abilities, allowing him to perform many superhuman feats. It also gives him superhuman durability, allowing him to receive most physical attacks with little to no damage, as proven when he was hit by a car and emerging nearly unscathed, with his body quickly recovering. In fact, Yūma's trion body has the unique ability to regenerate itself. In return, its durability is lower than that of ordinary trion bodies. Yūma's trion body also makes it so he never needs to sleep, although he still needs to eat and breathe.