Lentz serves as a second Lieutenant in the Black Knights, and he's defined by an almost zealous commitment to the organization—he'll do whatever it takes to advance their agenda, even if it means crossing ethical lines. That's what really sets him apart from his counterpart, Schneider, who has more restraint.
He's openly bigoted against Japanese people, frequently using dehumanizing language like calling them "monkeys." It's one of his most off-putting character traits, reflecting the worst of his faction's ideology.
That said, he's genuinely competent in combat. He's strong enough to break free from a restraint technique used by Kaita, a high-ranking member of the Sanada Ninja clan, and he leaves Kaita pretty badly hurt in the process. Kaita only survives thanks to Tsukayama Yutarou's medical intervention—so Lentz clearly isn't someone to underestimate in a fight, despite his other flaws.
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