Definitely Nerissa because she is more powerful.

Nerissa would win of course.Nerissa's element is the most powerful element in the universe and she is also much smarter and comes up with better plans than Icy.

Nerissa has borders ability, plus lightning is one of the most devastating elements know?

when it come to electrocuted, It’s not volts that kill poeople it’s the Amps….
you only need 50mA across your heart to kill you,
there is enough in a 9v battery to kill you under the right conditions.
in short if Nerissa can charge my alarm clock, she can fry icy like a fish stick?

and Nerissa is seen constantly shooting blots of full sized lightning,
witch carry up to one billion volts.
(im not even going to touch on her Ether magic as i doubt half of you know anything about spiritual energys)

her speed is far superior as well, as in the comics she is seen turning herself into lighting and traveling in split seconds.

Nerissa is also taking some serious punishment, shes been beaten physically by Khor and Shagon.
and still got back up and kicked some ass!

not to mention, Nerissa is very smart,
her plans are deep and complex, they aren't easy to figure out and guess within 2 episodes like icys are?

Y'all know Icy is my precious baby. But Nerissa is also my precious baby. And Nerissa's got a lot going for her power-wise.
I think they are both powerful but I think Nerissa is more so. And then there's the fact that she's already been shown killing someone on screen.
And she's got that whole invading dreams thing going on. And her 4 minions. Not everyone can craft minions out of ice, fire, and living beings.
Also probably helps that she was once the keeper of the heart which is the most powerful position in the W.i.t.c.h. saga.
It's was also really kickass when when she took over Matt's body and tricked Will into giving her the heart. Overall I love how she just managed to completely eliminate her own ability to love all together lol.
Lordy lordy I love Nerissa. All around great character. Well developed, powerful, complex...

But again Icy's really awesome too, I feel like her power would be much greater and her character much more developed if someone like took her away from Iginoi and gave her to a writer who actually gave a damn about writing her...

agreed ^
i feel like wouldnt be to quick to bash if icy had any depth, or general development?

I can respect that. Honestly I feel like some of the fans give Icy more development than is given to her by the creators and that's just sad. I love her, but shit, it's very clear that Iginoi doesn't. A good author cares about all of his/her characters and aims to develop them equally--Iginoi puts too much into his mains and nothing into his villains nor his cool characters like Mirta or Lucy.

And that's the pain of liking a kids' show. Honestly sometimes I don't even know why I bother with this show. Seasons 4+ were a freaking trainwreck...

Icy is quite powerful I am sure she would win.

@zanhar1: I don't think he gives too much to his mains, but I agree he should develop the villains more. As for Mirta, I kinda hate her now thanks to my sister, but other characters I wouldn't mind more backstory on, like the specialists.

What did your sister do lol? As in mains I'm mostly talking about Bloom and Stella, they got more background and general info than the other characters.

In the 2 pics Icy looks completely angry while Nerissa looks like she's in peace.

Yo, Nerissa's never in peace. She's mad like 99% of the time.

Give her a fair chance, and she'll take down each and everyone out there.

^ I can see that happening also lol.