Was discussing about Undertale soul traits with my friend and had the idea of classifying MP100 characters based on them. So.
Mob = Determination. Although I have classified him as Kindness before, Determination fits his entire self a lot since he has a) an intense desire to become a better person and b) a lifelong dream of getting to be himself freely one day. Determination is also a rather "neutral" trait, which reinforces how Mob is capable of doing both good and bad and only tends to do good due to the positive influence of his companions. Besides, he insists on following his morals no matter the situation, no matter how hard it may be.
Reigen = Kindness. LISTEN. This man has the complete ability to trick his clients into getting him more and more money, but he chooses to actually solve their problems. He claims his job is to dispell people's fears. Despite being stingy, he spent loads of money multiple times just to make the kids happy. He gave Mob a positive lesson even though he believed Mob was just an overimaginative kid. He made himself look bad for the sake of keeping Tome safe. This is a rude and selfish man but oh boy he is KIND.
Dimple = Patience. Most interpretations of the Patience trait agree on "waiting for the right oportunity to strike", which fits Dimple's strategy! He was a pretty tough spirit before, but instead of getting humans' attention by pure force, he researched about the most efficient ways to gain it with the least bloodshed and went through with the religion idea even though it would be painfully slow. He also waited a long time to gain Mob's confidence so he could eventually use his powers/body to achieve this goal.
Ritsu = Perseverance. Ritsu has long accepted that developing psychic powers is an extremely hard endeavor, even more trying to get to his brother's level. Despite that, Ritsu continues his attempts in nearly ridiculous levels of dedication (and lack of self-preservation, by following Mitsuura into a so-called lab he had never seen) even when following his goals would be weird, difficult or even unkind. Perseverance is a also a very similar trait to Determination, with the difference that its in-game description implies a more cautious, circunstance-based "trial and error" approach. Mob tried to be better because he wanted to be. Ritsu tried to get powers because he needed them.
Teruki = Bravery. This trait is commonly accepted as "rushing fists-first through all obstacles", which fits the method that he had to employ in order to survive Claw. Teruki is a rather aggressive person. He wasn't afraid of stabilishing his dominance over those he claimed to be commoners, and even after abandoning his "protagonist of the world" view, he doesn't care a bit about using violence to get what he needs. Teruki also pushed down his fears multiple times while facing much more powerful enemies. He is often in terrifying situations! Even so, he tries to be brave and smart enough to solve his problem as quick as possible.
Shou = Justice. Even though Shou was raised under Toichiro's influence to become a valuable member of Claw, he did everything on his power to stop his dad because he felt responsible for it. Sure, the organization was strong, and he would have plenty advantages by supporting them, but Shou didn't find it fair! He recognizes the evil Claw was doing to the world! He was alone and weak and unsure yet he faced his own powerhungry father because he didn't agree with such a horrible plan!