Using the Wishing Spell to kill someone, that's become one of the most common tropes in legends passed down through the ages.
And it is the most reliable wish that the Wishing Spell can fulfill.
Many people wish for great power or something else and often get played by the World Laws, ending up with some nasty side effects that stick with them, irreversibly.
But death is a very straightforward wish; just make it clear that your target should die right now, perhaps add a few details about the death, and there's usually no room for surprises.
The World Laws would be very willing to help you with this problem.
After all, if you hate someone enough to use the Wishing Spell to kill them, the price you pay should ensure an appropriate return.
But killing the Dwarf King, this choice was truly incomprehensible to Gustavo Flint.
What kind of grudge did this person have against the Dwarf King, and why kill the Dwarf King, and especially before the All Nations Conference?