Uchiha Clan (Naruto); via the Sharingan & Mangekyo Sharingan
Vinsmoke Sanji (One Piece)
Haoshoku Haki users (One Piece)
Owners of the Guardian Characters (Shugo Chara)
Bearers of Heart Eggs (Shugo Chara)
Users of the Emotional Spectrum (DC Comics)
Mutants (Marvel Comics)
Man-Thing (Marvel Comics)
Mr Pig (Pig Adventures Comics)
Rose Quartz (Steven Universe)
Steven Universe (Steven Universe)
Willow Rosenberg (Buffy the Vampire Slayer)
Daniel "Oz" Osbourne (Buffy the Vampire Slayer)
Magical beings (Charmed)
Tina Shepard (Friday the 13th)
Gwen (Sabrina Goes to Rome)
Werewolves (Teen Wolf)
Freya Beauchamp (Witches of East End)
Dash Gardiner (Witches of East End)
Werewolves (Wizards of Waverly Place)
Maggie Vera (Charmed 2018)
Edge (Final Fantasy IV)
Reaper Hosts (Jeanne D'Arc)
Spyro (The Legend of Spyro)
Spawny (Mario + Rabbids Kingdom Battle)
Sheriff Toothpick (Sly Cooper: Thieves in Time)
Ruby Rose (RWBY)
Kagerou's (Basilisk) breath becomes poisonous whenever she is sexually aroused.
Ichigo Kurosaki (Bleach) awakened his Hollow powers with his Inner Beast aspect and determination to protect others.
Saiyans such as Son Goku (Dragon Ball Z) can assume the Super Saiyan form through extreme emotional stress, such as anger.
Kurapika's Kurta Clan (Hunter X Hunter) can trigger their Scarlet Eyes when they are emotionally agitated.
Tina Shepard's (Friday the 13th) telekinetic powers involuntary activate when stressed.
Spawny (Mario + Rabbids Kingdom Battle) possesses unique reality warping powers that activate whenever he's stressed, which is often.
Sheriff Toothpick (Sly Cooper: Thieves in Time) can grow to a massive size when he becomes extremely enraged.
When tainted by Malefor's darkness three years ago, Spyro (Legend of Spyro) transforms under extreme emotional stress, when he was full of grief of his beloved mentor, Ignitus', sacrificial demise.
Sasuke Uchiha (Naruto) awakening and finalizing his Sharingan's tomoe after declaring his intent to avenge his clan.
Obito Uchiha (Naruto) awakens his Sharingan from his determination to protect Rin and Kakashi.
The Mangekyō Sharingan (Naruto) is awakened by the trauma suffered from witnessing the death of someone close to the Sharingan user…
…Obito Uchiha & Kakashi Hatake awaken their Mangekyō Sharingan after witnessing Rin's death…
…Itachi witnessed his best friend’s death and sacrifice…
…Sasuke after learning the truth about his older brother's sacrifice…
…and Madara after his brother's death.
Whenever the Jinchuuriki (Naruto) become upset enough, they can access their respective Tailed Beasts’ power.
Steven Universe (Steven Universe) possesses a wide-range of gem-powers all tied to his emotions, such as the ability to control his age, the velocity of his ascent and descent and the ability to summon his shield…
…various abilities inherited from his mother Rose Quartz.
The Man-Thing (Marvel Comics) generates corrosive acid in response to fear, including its own.
Ruby Rose's (RWBY) silver eyes are triggered by feelings of love.