“When the owner of the four-leaf grimoire is filled with despair, the five-leaf clover grimoire will be born.” Patry is filled with despair after learning he had been manipulated by the devil all this time and turns into a dark elf. He then starts attacking Yuno and Asta, fueled by nothing but hatred and malice. Somehow, becoming a dark elf had made Patry even stronger, which gives Yuno and Asta an even harder time fighting him. Then Captain Nozel appears before them. Nozel happens to have the best magical attribute to fight against light magic, mercury magic.
The final state of an elf who's 
overflowing with malice...
...آخر مرحلة لإلف يغمره الحقد
Als das hasserfüllte Ende eines Elfen …
Un elfo que sucumbe a su maldad…
Un elfo que sucumbe a su maldad…
Un elfe qui finit par succomber
à l’esprit maléfique…
Ecco ciò che diventa un elfo 
quando viene sopraffatto dalla propria malignità...
O estado final de um elfo
carregado de maldade...
А вот и конец эльфа,
чьё сердце поглотило зло!