Kevan, the Earl of Io, may challenge Elodie to a duel to the death. If Elodie has sufficient mastery of her Lumen skills, she can instantly burn him to a crisp while delivering a Bond One-Liner.
On that note, if your skill in Swords is high enough, you can accept his challenge, and then beat him in a fair fight.
Alternatively you can fight him with a staff and beat him. Kevan will be so out of himself he'll try to break the rules and force you to strike him down. You can talk him out of it with enough of the right set of skills, as the game itself puts it: "The applause of the crowd is deafening."
Yet another option consists of training your falconry skill to max level, then choosing the Falconer contest. When Kevan shows up, your falcon will swoop in and hack away at him like the true BadassAction Pet it is until he's detained. Remember that Kevan wears plate armour and is almost impossible to kill with magic.
To be precise, you defeat Togami by using the sole area of combat Togami isn't an expert in: a physical attack. You create a sword made out of magic and cut off Togami's head.
And an understated (and very tricky-to-get) version is if you manage to get him to stop the war by singing to him, then appealing to him to think of his children, and what might happen if they lost their father.
The epilogue for this one reinforces it - among the gifts the Shanjian trade-ship brings to Elodie, there's two paintings of "a pink-haired angel" obviously made by children.
Prior to the duel, it's possible to actually drive off the fleet altogether, preventing their army from even making it to your shores, making Elodie very popular amongst the commoners.