[Assuming HSBC]
i think he deserves the consequences of his actions but i dont think killing him would be the most interessting story
he certainly plans to be killed (by dave) and he might get killed (by someone else) but i dont see him getting the death of a true villain (though no doubt it will most likely be just)

in the hypothetical of [me] (human self insert) killing dirk i think id have good chances as Witch of Light to manipulate his Relevancy, bending the Spotlight around him and see him self destruct in the attempt to escape unimportance

hypothetical of [me] (trollsona) it would go similar, however i think it'd be a bit more troublesome bc of the troll aversion he carries making him more volatile

of [me] (trollsona ancestor) i dont know if i could kill him, bc while as Maid of Light id likely be unkillable through sheer luck, but i think missing the offensive capabilities for the most part to be able to overpower him. i think he is too smart and cautious to fall for traps for the most part, though i might be able to maneuver him psychologically into a corner by discourse