The Guardian Angel Protecting a Child from the Empire of the Demon

英語で読む ハリーポッターとアズカバンの囚人 第12章-4「守護霊」

闇の魔法使いの身でありながら、怒りに駆られて守護霊の呪文を唱えたラクジディアンは、なんと自分の杖から飛び出した蛆虫に食い尽くされて死んだそうです。 ナム(-人-)


最後に HP Wiki さんの Patronus Charm から、一部を抜粋して紹介します。


It is a general belief held by the wizarding world that only those who are pure of heart are able to cast Patronuses; this, however, is untrue, as several characters with negative personality traits are able to cast a fully-fledged Patronus. Although generally Dark witches and wizards will not try to produce a Patronus, not having any need for one, most Dark wizards will be devoured by maggots coming from their wand and consuming the caster.

For this reason, Lord Voldemort and his Death Eaters were not able to cast a Patronus Charm (not that it was necessary, as they already had the dark creatures under their control via their affinity to darkness, and would have no use for Patronuses). However, some witches and wizards of questionable morals, such as Dolores Umbridge, are able to produce corporeal Patronuses, Umbridge doing so despite the fact that she was considered an evil person; her wearing of Salazar Slytherin’s Locket, which was one of Voldemort’s Horcruxes, was what enhanced her strength due to her evil affinity. She was able to produce a corporeal Patronus due to the enhanced strength. Conversely, Draco Malfoy was unable to cast one despite his waning evil. Severus Snape is the only Death Eater capable of casting the charm, as his love for Lily Evans was his one redeeming point.
Patronus Charm | Harry Potter Wiki