You need to remember how wizards think. If the killing curse can’t be blocked by spells, then it simply can’t be blocked. They mean that if you use it in a duel, it doesn’t matter what sort of shield spell your opponent has up, it won’t work, and so the spell isn’t very sporting and therefore is unforgivable.
You need to remember how wizards think. If the killing curse can’t be blocked by spells, then it simply can’t be blocked. They mean that if you use it in a duel, it doesn’t matter what sort of shield spell your opponent has up, it won’t work, and so the spell isn’t very sporting and therefore is unforgivable.