He looks to have great synergy with the upcoming Star Lord. Star Lord can summon him on the cheap with his ability, and then he can enable Star Lord to use SL's ability and minimize the impact of the resulting encounter card.
The best combo for this is a Rocket Launcher blast that hits 2+ targets (one or more minions and the villain) for 4+ damage.
Also, am I correct in assuming that the "you" on this card means Rocket does NOT heal any damage when an ally deals damage?
This card is superb, there are just TONS of great targets for it. Early game you can get a support like Helicarrier, Avengers Mansion, or Quincarrier on the table at a discount, which will really accelerate setup for a LOT of different heroes. It also removes some of the tempo cost of playing temporary resource generators like Enhanced Physique.
The basic set also has some great staple allies that you will play in the mid to late game, as well, like Mockingbird, and Nick Fury, or in the Wasp preCon you have Ironheart and Spider-Man.
In the late game this card is still useful as an unconditional wild resource which is always handy for discarding Villain attachments.
Don't sleep on this card, it will improve a LOT of decks.
All three options on this card are decent, but not amazing. This card is very flexible, letting you split up your damage/thwart across 2 targets, or apply it to just one target.
A key thing to point out here is that, while the card is a Hero Action, it is NOT an Attack or Thwart event, so this card bypasses Stun, Confuse, and Guard.
Due to the wording on Crisis, this card cannot bypass Crisis Icons.
Quicksilver's ability is limit once per phase. The villain phase is separate from the player phase, so you can (and should) exhaust Quicksilver to defend on every Villain attack you can, since he will instantly ready after doing so, and this will NOT prevent you from readying on your next turn.
If going all in on the Protection aspect, you can even exhaust to defend an attack that targets you, ready Quicksilver due to his Super Speed ability, and then Exhaust to defend an attack targeting another hero. You won't instantly ready after the second attack, but if you have Always Be Running that may not be a huge issue.
Quicksilver combos very well with a teammate running Leadership, so you can stack up Attack and Thwart buffs like Lead from the Front and Morale Boost on a turn you have several copies of Always Be Running and smash the villain or main scheme with multiple huge hits.
Aggression also works great, since Friction Resistance combos very nicely with Jarnbjorn.