I've been experimenting with this card and have been really appreciating it's niche in solo and multiplayer (2p). Five threat per player and 2 ER is on the expensive side for a PSS, but it provides a great upgrade for any character that wants to use their basic powers or even face tank. Game Design Raccoon's review rightly, and helpfully, provides each card's stat bonus, but each specialization card also gives you card draw when using that bonus.
In solo play, this card is easiest to fit in Justice or Leadership decks that have lots of thwarting options, but it's playable in any aspect if the hero has strong thwart. Unleashed Phoenix with 4 basic ATK is very strong, especially when combined with Utopia for re-readies. Rocket with 4 base THW (including his Thruster Boots) can deal with a lot of side schemes with just his basic thwart and he has re-readies with I've Got a Plan and C.I.T.T. Defensive Specialist is probably the hardest to make good use of in solo, as you'd want a character who benefits from high defense AND has good thwart options (maybe Angel or one of the Spiders?) -- but my protection team mates in multiplayer love it when I clear this PSS and they effectively get an extra copy of Unflappable.
It's a bit clunky, and Marvel Champions usually rewards smooth play, but this can be a powerful card.