This card flew under my radar at first when looking at the 'Pool cards, but once you realize the things you can do with it, it opens up a world of possibilities.

Most obviously, if you start the turn in hero form and flip to alter-ego, your hand size just went up 1 or 2, so Mulligan draws you a free 1 or 2 cards.

Now, let's look at that key first line: "You cannot play this card if you have played another card this phase".

This provides 2 work-arounds: Doing things with your cards that are not playing them and doing things during the villain phase.

For the former, a bunch of 'Pool cards fit this category: Tic-Tac-Toe, Blackout, Plot Convenience, Deadpool Corps Ship, and Stick-To-Itiveness. For the latter, Not my Responsibility, Get in Front of Me!. For both categories, some basic and identity-specific cards will work too. For example, Machine Man and Plan B.

If you can do either of these, then Mulligan will give you a net gain of cards in hand. Even without these tricks, some decks will just want to go through their deck faster to get to some specific cards, in which case Mulligan is also great.

Overall, a sweet card that helps contribute to the unique feel of the 'Pool aspect!