Guts, the Blackswordsman (Berserk) is a rage-driven warrior capable tearing apart even demonic beings and surviving punishment that would kill a lesser human many times over when he goes berserk.
Kenpachi Zaraki (Bleach) is prime example of a berserker, able to ignore fatal strikes and overcome his opponents through sheer ferocity and blood thirst alone.
In his Bankai form, Kenpachi Zaraki (Bleach) becomes a mindless, feral berserker unable to differentiate between friend and foe and fighting without any regard for his own safety.
Fullly Transformed Hollow Ichigo (Bleach)
Saiyans, such as Son Goku or Vegeta (Dragon Ball series), have a born instinct to fight despite whatever ailments they may receive, showcasing their status as natural born fighters.
Due to her suppressed frustrations, when Kale (Dragon Ball Super) transforms, she becomes a nigh-unstoppable berserker attacking anyone she can direct her anger against.
Already having immense anger issues and traumatic experiences, Broly (Dragon Ball Super) becomes a a nigh-unstoppable, mindless berserker when he tranforms.
Gaara (Naruto) lost control over Shukaku when Yashamaru made him believe that nobody would ever love him, causing a rampage.
In the Jinchūriki Form Version 2, Naruto (Naruto) is unable to distinguish between friend and foe, attacking in whatever way will enable him to defeat his target.
Jūgo (Naruto) goes into a berserk rage whenever he lets the natural energy he passively absorbs cause his body to go out of control.
If Inuyasha (InuYasha) were to ever drop Tessaiga in battle and his life is in danger his demon blood takes over sending him into a berserk, feral stage.
Before mastering and gaining control of it, Tony Tony Chopper (One Piece) would go berserk as Monster Chopper whenever he ate three Rumble Balls within a six-hours time span.
When Cavendish (One Piece) falls asleep, his sadistic alter ego, Hakuba begins rampaging, killing allies and enemies alike.
Charlotte Linlin (One Piece) becomes a dangerous berserker driven by her gluttony for sweets.
Kaido (One Piece) is ruthless and brutal pirate captain with a bestial hunger for war and chaos.
Nizō Okada (Gintama) goes completely berserk after being taken over from his fusion with Benizakura.
Kagura (Gintama) losing control to her Yato instincts, becoming a berserk fighter.
Kamui (Gintama) losing control to his Yato instincts, becoming a berserk fighter.
Knowing Demolt (Zatch Bell!) wouldn't cooperate because of his savagery, Zofis brainwashed him with his powers. But when Demolt’s bookkeeper, Roberto Vile cast the Girugadomu Barusuruk, he was freed from Zofis’ control and returned to his berserk personality.
Girufadomu Barusuruku is a forbidden spell that turns Riou (Zatch Bell!) into a giant monster, in this form Riou had no control of himself and attacks allies and enemies alike.
Whenever her partner, Lori casts the spell, Zeruku, Kolulu (Zatch Bell!) gains a fearsome transformation of which she attacks her opponents without mercy.
Allenby Beardsley (Mobile Fighter G Gundam) with the Berserker System activated by her handlers.
Issei Hyoudou (Highschool DxD) loses all control and becomes a berserker after activating Juggernaut Drive.
Irene Belserion (Fairy Tail) can enhance Alvarez soldiers to be mindless monsters with her "Berserker" spell.
Utsutsu Hasegawa (Pupa) losing control to his Pupa instincts after learning what his "sister" really is, becoming a berserk monster.
Basara Toujou (Shinmai Maou no Testament); losing control of Brynhildr temporarily awakening his demon lord blood causing him to lose control of himself granting him the strength to overpower a low-tier god, this is trumped by...
...by his full Demon Lord form, which remove the seal on his true mother's blood granting him the power to overwhelm the current Demon Lord.
Saturn (Marchen Awakens Romance) transformed into an enormous canine-like monster after his Darkness ÄRM, Finsternis was destroyed. In this form, Saturn has absolutely no restraint and mindlessly attacks everything around him.
Kahlua Shuzen (Rosario + Vampire) is an exceedingly powerful vampiress who has been charmed to be immune to pain
; when under the effects of the charm, she will blindly attack her opposition and kill them without remorse.
As a Kishin, Tenmei Mikogami (Rosario + Vampire) is a nigh-unstoppable berserker when in battle, which is why he usually keeps his powers sealed.
When her seal is broken, Muru-Muru's (Mirai Nikki) apearance alters and her moves become wild and erratic.
Hibiki Tachibana (Symphogear) enters a berserk state under extreme stress, when her appearance darkens to the extent of becoming jet-black with glowing red eyes and aura.