Limbo + 'Pool = Hot Tub

Magik is a very straightforward hero to build in my opinion as most of the cards she wants are basic, therefore I just added in a few cards from an aspect to help power her up even further.

Healing Factor balances Bloodgem. Rock Paper Scissors is a free card every turn since you know what the top card of your deck is.
Stick-To-Itiveness + X-Jet is an extra ready every turn. Headpool is a 2 THW ally with 0 consequential damage that has extra utility in minion heavy decks. Similarly Cosmo will never take consequential damage here either. Legion can keep himself around for a long while as well.

Otherwise everything else is fairly explanatory. Build Support helps get Limbo out and Specialize Training can give her whatever you need in a given game, be that extra HP, ATK, or THW(my usual choice).

Since everything in the deck is fairly cheap and she'll have an outrageous number of cards in hand, you won't need the basic resources and they'll slow you down, a mere 3 Digging Deeps is plenty.

Digging Deep/White Fox + Limbo + Cosmo/Legion means that you'll have more free cards every turn.

Professor X gives you a ready, or confuse and provides a ton of threat removal. Angel is just some extra damage which I found I was lacking, but it otherwise a cheap body and may be swapped for Ironheart.

Triage is perhaps the best and most broken ally they've printed. 2 healing + 1 ATK/THW + defender for 2 resources is even better than Ironheart(who narrowly misses the cut in this deck).

If you're wondering why 41 and not 40 it's because of Spiritual Meditation. I was originally running x2 but it's so useful here that I couldn't not include the third.