Fabricati Diem, Pvnc

Tsurumi is sketchy but popular, let's exemplify this as him taking advantage of young men (canonical interview note). His manipulation of Edogai shows off how he's got a strong hold over the troops.

Tsurumi varies his approach based on the target, he is equated to morphine with Nikaidou, he pulls on Nikaidou's levers via drugs and revenge rather than personal appeal

Tsurumi employs sexuality in his recruitment process as a metaphor for ideological conversion, he 'seduces' and seduces Koito to his cause, tries to do the same for Ogata, he encourages violence and sexuality in tandem

Tsurumi does tend to target young men to reel in bigger prizes; Koito and Ogata are both relevant to Tsurumi for their fathers.

Tsurumi keeps control over his inner circle by constructing so many layers of falsehood that it's impossible to gauge his true intentions, so even people who feel their levers being pulled get confused and give up (Tsukishima).

Usami is the first of Tsurumi's inner circle and the only one he fears. Tsurumi's only lever for control over Usami is sexuality, Usami has no inhibitions when he's a kid and doesn't fear or acknowledge the consequences of his unbridled (heh) violence.

Tsurumi's methods aren't just standard manipulation, pulling levers on people as they are; his methods are active attempts to reduce other people he meets to children-animals, incomplete and irrational people. Usami explains to us that Tsurumi isn't just figuring out what works for his various soldiers, it's him trying to eliminate any compassionate impulses in them and replace those with himself, it's about fostering that addiction, Usami's story redoubles the Tsurumi-Opium parallel of Nikaidou's storyline. The power of love being a force for evil is one of GK's best ideas, one of the most insightful ways it portrays fascism and fascist tendencies.

This tendency spins off into a different habit that I really love, which is that events that are critical to main characters' lives don't always line up with what is critical to the story. Tsurumi's origin in the samurai classes puts a massive spin on his character, revealed in passing in a comedy subplot. Kikuta's time as a spy, ditto.