The fear of uncertainty frightens Togevee, to the point it stays in its shell as it knows it's the only thing that'd never change. Togevee also stores its happiest feelings in its shell, making them prone to evolving into a form of Sylveon.
An Togevee has an unstable genetic makeup that suddenly mutates due to its environment. As its energy, it uses the feelings of compassion and pleasure exuded by people and Pokémon.
