Conversion into Demons
Possibly related to their ability to cross-breed, humans can also transform themselves into demons, when exposed to high amounts of demonic power. This change always create a rise in power, as well as an often dramatic change in appearance, as the person takes on a demon form. Some of these hybrids have even had the power to rival the descendants of Sparda. The Devil May Cry 3 manga also shows that this process can be forced upon, though the results are still the same.
The methods to change a person into a demon are varied, though the source of the demonic energy tends to theme the transformation, such as the angelic theme of the Order of the Sword. The confirmed methods are the Ascension Ceremony and the use of the Arcana, though the Temen-ni-gru is credited inside the manga to be used to convert scholars of demons.