Leaving some ideas here:
Sasaki Tadasaburō & Imai Noburō: Members of the Miwamarigumi (similar to the Shinsengumi, but composed of higher-ranking samurais and sons of the shogunate's retainers). They don't have cool feats like Okita or Hijikata, but they confessed to have been the ones who killed Sakamoto Ryōma, so something could be done with that as a basis. They could have
Scapegoat as a reference to how Kondō was accused of killing Ryōma, although it's not as if they blamed him directly.
Kagutsuchi: The kami of fire who killed Izanami by accident during his birth. He should be really OP since not only he killed a goddess, but also introduced the concept of death in the Japanese creation myth. As for the class, he could qualify as Saber (patron of blacksmiths, plus he was killed with a sword), Assassin (first to kill somebody), and Berserker (in a version of the myth, the water kamis were created to pacify him).
Gustave Eiffel: This one may result harder to do. The Eiffel Tower is the most obvious NP. One of its functions would be nullifying the Fame of anything in a large area, but that doesn't look like enough reason to build a 300-meter tower. Another NP could be the Statue of Liberty as a golem. Also, aerodynamics. Eiffel loved aerodynamics.
Tamiya Iemon & Oiwa: The main characters of Jaoan's most well-known horror story, the
Yotsuya Kaidan, which by the way looks as if Shakespeare went to Japan on holiday. There's a very famous picture of Oiwa's ghost emerging from a paper lamp made by Hokusai, and her character inspired the famous Sadako. As for Iemon, he ends up becoming crazy for being haunted all the time, and gets pissed off many times during the play, so he could be a Berserker.
Marduk: He soloed Tiamat at her strongest and her 11 children, so strongest god ever? Any idea I have for his NPs is basically Gil, unfortunately. I mean, his weapon Imḫullu is basically
Ea, and his net of the four winds does a better job at binding than
Enkidu since Tiamat couldn't break free from it. I had an idea for the latter that made it a Bounded Field preventing development by means of constant erosion, which prevented that Tiamat used her
Monstrous Strengthor
Self-Modification.