How about some of the words that describe groups which actually were known for this (or similar) intimidation tactics, one video game/psychology theory, and a common troupe. The first and last are very common terms/legends used for this while the second provides some names used for this behavior based on a psycho-analyst model:
úlfheðnar and <PERSON> & the Kaikusi Yumu
Though originally two groups these are now both more commonly lumped together and referred to as Berserkers. These were two shamanic groups which were known to invoke an animal totem/spirit (the wolf and bear) to intimidate their enemies and build themselves into a rage state which helped to dehumanize themselves (making brutality easier and lessening the effects of fear) and creating an altered-state which allowed them to ignore pain easier 1 & 2. To do this they would perform rituals which included biting their shields and howling or roaring at the enemies3 (some say it included drinking blood or other self-harm events) before and while heading into battle. It's actually the inspiration for a TV trope known as the screaming warrior which has been used in numerous shows and video games. It was also effective as these warriors became legends which were said to be immune to damage from fire or iron 1 & 2 & 3.
These were not the only warriors to invoke animal spirits and practice rituals to build themselves into a rage. 72
Carib warriors would try and be possessed by the Kaikusi-yumu 4 the tiger spirit or tiger demon. This spirit would stay inside him until he ate the heart or drank the blood of a slain enemies.
Jungian Psychology and Persona
The Persona video games directly borrow from Jungian Psychology and in these games - you must do something painful to activate your powers (like shot yourself in the head or rip a bloody mask off your face). This comes directly from <PERSON> who postulated that an emotional shock or trauma would split off some of our psyche and create a complex 5.
So <PERSON> gives us 4 really cool names based on his archetypes: the Shadow, the Animus and Anima, and the Persona - many of which involve pain (or trauma) to develop further (or more correctly dealing with the trauma). In fact, one of the earliest (no longer followed) of <PERSON>'s methods was to have people relive and retell their trauma in order to deal with and grow - a process called Abreaction.
Of Terror Knights, Black Knights, and Sith
Many games and movies/tv, have a class of Knight which use attacks and actions that cause themselves damage in exchange for beneficial or combat effects. Such as Tactics Ogre, Final Fantasy, and Star Wars - they are also used in legends and as a representation of <PERSON>. These groups usually use some form of negative energy (whether derived from demons, blood magic, negative emotions, etc) to fuel their spells and abilities and thus either experience a form of blow back from them or actually have to physically damage themselves to even access them.
1: <PERSON>, Ancient Germanic Warriors: Warrior Styles from Trajan's Column to Icelandic Sagas, Routledge, Aug 2004, pg.38-40
2: Transforming Warriors: The Ritual Organization of Military Force, Routledge, May 2016, pg.55-57.
3: <PERSON>, "Bare or Bear, or, the Story of Berserk", 2008.
4: The Anthropology of War, Cambridge University Press, Jul 1990, pg.151-152.
5: "A Review of the Complex Theory," CW 8, par. 204. 72