W.I.T.C.H., Season 2

Irma:
Okay, see I didn't bring my who's who from Kandrakar, so Nerissa is...?

Oracle:
As you know, you are not the first Guardians. Decades ago there were five others. Cassidy, Halinor, Yan Lin, Kadma... and Nerissa.

Hay Lin:
They were C.H.Y.K.N.? Wow, I'm so glad we're W.I.T.C.H.

The Oracle:
[voiceover] [as the camera pans across W.I.T.C.H, the scene transitions to one showing the former Guardians] Nerissa led the Guardians as Keeper of the Heart of Kandrakar, as you do Will. But I sensed [Nerissa holds up the Heart and sees it glow through a shot of her eye] the power of the Heart was corrupting Nerissa. To save her soul, [The Heart is shown floating and given to Cassidy] I took the Heart from her and gave it to Cassidy. [Nerissa, shocked, walks away] But Nerissa became obsessed with her lost power. [Nerissa and Cassidy are atop Mount Thanos] After begging and pleading, she demanded Cassidy return the Heart. Cassidy refused.

[Nerissa casts a lightning bolt at the cliff, and Cassidy falls to her death, Nerissa is shocked by her actions]

The Oracle:
[voiceover] [Nerissa runs across the cold of the mountain] Devastated, Nerissa fled. [An energy cell appears around Nerissa in a cave inside Mount Thanos] But I imprisoned her. [scene shows Yan Lin, The Oracle and Halinor standing outside her cell] Hoping that she would redeem herself [Nerissa lifts her head up] by facing her guilt. I fear [Nerissa's youthful face changes into the old Nerissa] I may have aired.