Higashi Setsuna

Setsuna is one of the official characters of the Pretty Cure franchise. Her alter ego is Cure Passion (キュアパッション).

Canon
Setsuna starts out as a cold and isolated girl, loyal only to Moebius and act sly. When she, as Setsuna, meets Love, Love's nature and the "happiness" Love shows her makes her slightly open up to the girls. She begins to open her heart, cracking piece by piece to them, but too stubborn to realize it. She have a stubborn mind, however, as she refuses to accept the fact that she has weaknesses. This is shown every time Soular or Westar asks her about Pretty Cure after losing to them, in which she throws small fits and leaves, usually thinking that she will be the one defeating Pretty Cure.

After switching sides, she seems to have lost most of her stubborn mind, and is typically sweet and reserved and patient, though her nature may be due to naivety and guilt when she remembers her sins of doing evil things hurting her friends in the past but over it when she faced "herself". She became kind hearted and loves her friends and Setsuna and Love were like sisters.

Fanon Description by Caramelangel714
In The Mega Man crossover, Setsuna's alter ego is Jewel Passion (ジュエルパッション), combining with Jewel Man's power.

Fanon Description by Rispba
Setsuna was on Team Ryutaros during the TimeWarp Precure/Kamen Rider Den-O Cross-over. Under the control of the Purple Precure mind, which was possessed by Ryuutaros at the time, she helped TimeWarp Precure defeat Rideless.