During my first couple of times playing Magik I missed that her unique ability is 'once per phase' rather than 'once per round'. This means that she can use her ability to play Magic Barrier (for free) off the top of her deck during the Villain phase, and then play another card with that ability during the Hero phase.

With Limbo, Stepping Discs, and her alter-ego ability, it is very easy to have a Magic Barrier available to play for free during ~most~ villain phases. Great card!