Asura (Asura's Wrath) enters his Mantra form through this.
Even with his easy-going attitude, Goku (Dragon Ball Z) felt rage at the loss of his friends when he faced Nappa ...
... and even with his heart tainted of seeing his best friend, Krillin, die before his eyes, it was a quiet but fierce battle against Frieza.
Princess Unikitty (The Lego Movie) has a powerful anger which she keeps intact with thinking positive.
Kurama's (Yu Yu Hakusho) anger made him act on impulse to kill Gourmet and sentencing Toguro into a lifetime of suffering.
Despite Doflamingo's (One Piece) relaxed attitude, he does have a temper, shooting Law three times, his plans for SMILE ruined, being dethrone, Luffy's interference and desperation to kill him, he still retains his trademark smile because he couldn't get any madder.