Summary
White Widow supports one of the most complicated archetypes to play inMarvel Snap; the clogging archetype. The idea behind it is to fill your opponent with useless cards, preventing them from developing their board and usually having them retreat.
The way White Widow does this is by putting a Widow’s Kiss on their side of the board. Unless they fill that location, the Kiss is going to give them -4 power on that location via its ongoing ability, a heavy blow to any deck, particularly the ones that play just a few big things.

7Black Widow
Sisters Unite
Cards from the same series rarely share abilities; you only need to look at the Fantastic 4 to see a group of cards you can’t make a deck out of. The Widow sisters, however, not only belong on the same deck, but also complement each other well.
Black Widow sends the Widow’s Bite to your opponent’s hand, a -1 power card that prevents them from drawing as long as they don’t play it. You need to be careful when you give them the Bite, since it might help them negate the effects of the Kiss.

6Darkhawk
The Big Bird Is Back
Darkhawk has rarely seen play after his biggest nerf, but he fits nicely on a deck with the Widow sisters. His real synergy comes with Black Widow, since she denies your opponent from drawing for a turn, which translates to 2 more power for the Hawk.
This is because Darkhawk gains +2 power forevery card still in your opponent’s deck, meaning that the bigger it is, the better for you. Remember that Darkhawk always needs some form of support, so always include Korg and Rockslide when making a deck with him.

5Beast
Good On Reveals Are Better Twice
With so many cheap on-reveal cards, you need some way of making use of their abilities more than once. Beast is ideal for this, since he not only sends cards to your hand, he also makes them cost one less next turn. The only thing to keep in mind with Beast is the surprise factor, or lack thereof.
The first time you play White Widow, you might catch your opponent by surprise, but after Beast, they will know what’s coming and how to prepare accordingly. With this in mind, you should aim White Widow not at a surprising location, but one they can’t possibly fill this turn. That way, White Widow is more than just a two-powered card, becoming an absolute denier of plays.

4Debrii
Clogging Everyone
Debrii sends Rocks to all other locations, not only on the side of your opponent, but also to yours. This means that you need careful planning when playing Debrii, but when your plan is to clog your opponent, she’s a must-have.
In a way, you are helping your opponent fill up the Widow’s Kiss location, but it’s all about timing. If you are the one filling the location, you might remove the negative power from the Kiss, but you’re also giving them a useless Rock that you can easily beat with nearly every card.

3Annihilus
Send The Garbage Over
It’s not a bad idea to have a way to deal with your own cards, since many decks have ways to use them. Things like Mirage, Baron Zemo and Loki often use your power against you, so being able toreturn the favor with Annihilus(sending cards with negative power to your opponent) is often a game-winning move.
Yet you don’t want to simply have Annihilus, since on his own he only offers six power. The Hood fits nicely with all other elements of your deck, and Sentry can go from ten to 20 potential power thanks to Annihilus sending the Void over.

2Mockingbird
Using All Those Rocks To Your Advantage
While clogging your opponent is all well and good, you also need power of your own to win games. Since Mockingbird’s cost isreduced for each card in play that didn’t start on your deck, something as simple as Debrii can lower her cost and allow her to be played early.
Her cost is lowered by other cards as well, not just the Rocks. Sentry’s Void or The Hood’s Demon are, after all, cards that didn’t start in your deck. Just be sure to play Mockingbird before you send their negative power over; otherwise, she loses her discount.

1Carnage
Cleaning Your Side Of The Board
Having a way to clear locations after you clog them will allow you to win games more easily, since you don’t always have a way to contest power with a single card. The best way to do this is with a destruction card, and Carnage is the best option among them.
Since Carnage is so cheap, be sure to play Mockingbird before destroying all the rocks. That way, you benefit from them with two cards instead of one.
Carnage gains the most power when compared to anything else, he only affects your side of the board, and he’s incredibly cheap. This lets you bounce him back with Beast, clearing not only more rocks later, but even the Void if you don’t manage to draw Annihilus.