She often uses illusion to alter her appearance, in particular her hair length, style and colouring. Before she manifested that ability she used to dye it. Her eyes are naturally grey and she usually keeps them this way. She's 5'9 and very slim. Her hair is currently a dark blonde, long and skewer straight.
AbilitiesThe first ability she manifested was Psychokinesis, aged 23. This is a highly advanced mental ability, which includes hearing and altering the thoughts of others, in all languages, as well as causing hallucinations, verbal persuasion, controlling consciousness and hypnosis.
The second ability she manifested was Illusion. She can use this to alter her own appearance and the appearance of her surroundings, tricking the senses of others. She often uses it to change her appearance, in particular her hair. The ability functions by bending light and air in order to make reality seem as she wants it to appear.
Her last ability is Longevity. This ability prevents her from aging, making her effectively immortal unless killed. It also improves her health and makes her less susceptible to illnesses, but she does not heal if injured.
- Mother - Nia Courtey
- Father - Andrew Courtey
- Paternal grandfather - Caradog Shaun
- Adoptive younger sister and cousin - Lowri Petrelli
- Brother in law - Peter Petrelli
- Nephews - Nathan Petrelli Jnr, Nathan Petrelli Snr, Darrien Petrelli
- Nieces - Amber Petrelli, Hayley Petrelli, Tessa Petrelli, Lucia Petrelli
- Niece in law - Dani Petrelli Snr
- Great-nephew - Alec Petrelli
Cadi grew up in the same small West Wales town as her sister did, and was given her abilities at around the same time. William Williams also checked what abilities she too would gain before doing this, to ensure she'd be able to cope with them. She was briefly forced to hide from B26, but nowhere near to the extent that others had to. She also manifested psychokinesis at this time, and was freaked out over it until Lowri eventually managed to calm her and reassure her that it was a good thing. However, she still has never been completely comfortable with being an evolved human, and tries to ignore it as much as she can, using her abilities only briefly and subtly. She does help the Organisation sometimes, but only at utmost need, usually when a psychokinetic in needed, and also usually at her sister's prompting. She has manifested another 2 abilities but is currently unaware of her longevity, since she's yet to notice how she's not aging.
Cadi is a pet form of the Welsh name Catrin, which means "pure". Her middle name, Heledd, may mean "princess". Her surname is derived from "courtier".