Crudelis: Latin To delight in blood and gore. Over time this word came to mean being vicious and cruel
The word Crudelis comes from an even older word in Proto-Indo-European, simply Kru which means blood, gore and viscera.
Kru words show up in the English language a lot in association with bloody and awful deaths.

Cruentous: Bloody (from Latin)
Cruentation: The ooze of blood when a body is cut open (Medical)
Recrudescence: To begin bleeding again (Medical)
Cruet: A small wine bottle that contains red wine/the blood of Christ during Mass.

Crucifixion: A cross made of fastened together tree trunks in an X shape, used as an instrument of torture and death.
Excruciating: The word originally coms from the pain of a crucifixion on the cross.
Crochet: A form of needle-work using a little hook.
Kruella De Ville: the notorious character from the Disney film 101 Dalmatians who wanted to skin the poor little doggies alive!

References
An Etymological Dictionary of the English Language By Walter W. Skeat (1910)