So, let me first say, MEV is a really cool, VASTLY powerful set. Over on VSrealms, at least one infinite combo has already been discovered, and I highly doubt that it will be the first. Now, I'm not nearly clever to truck with that sort of shenanigans. I'm not a good enough deck-builder, after all, and I'm not quite mean enough. I like being annoying as much as the next gamer, but there are limits.
Still, I like being annoying more than enough for this deck right here. As you've all seen, I'm a big fan of the Bring Your Own Two Team format, as I love team-up decks and I love not having to worry about hitting team-ups. Of course, there are downsides, and these two teams certainly highlight those downsides. The Spider-Friends have been a powerful team for a couple years now, but that's far more thanks to the suite of Spider-Man support cards, most notably Gift Wrapped, and their normal, team-stamped effects are generally fairly dull. Meanwhile, X-Factor, a team I had high hopes for in MEV is virtually unplayable on a budget, having only 3 non-rare support cards (1 of which is a team-up) and, in their rare support cards, 6 of them are legend stamped.
This brings up a fair question: why on Earth build Spider-Friends with X-Factor if their support suite is so lacking? Well, I'm just gonna print out a few card effects really quickly, and I'll let you take it from there...
Team: X-Factor, Purifiers
[Activate] -> Gain 1 endurance for each character in play with an activated ([activate]) power.
Siryn, Sonic Scream
Team: X-Factor, X-Men
Whenever a character's activated ([activate]) power is used, target opponent loses 1 endurance.
Madame Web, Cassandra Webb
Whenever an activated power of a Spider-Friends character you control is used, gain 2 endurance.
Activate -> Look at the top two cards of target player's deck. You may put those cards into that player's KO'd pile or on the top of his deck in any order.
Fun and Games
To play, discard a Spider-Friends character card.
Ongoing: Characters have "Activate -> Negate target activated effect an opponent controls."
(taken from docx's excellent search engine)
Do you see how things might play out in an interesting manner?
8x Multiple Man, Army * HYDRA
2x Layla Miller, Butterfly
3x Rictor, Depowered
7x Jamie Madrox <> Multiple Man, Army * Agent of SHIELD
3x Beast, Wild and Wooly
4x Madame Web, Cassandra Web
3x Siryn, Sonic Scream
1x Strong Guy, Guido Carosella
4x Empire State University
4x Falls Edge
3x ESU Science Lab
4x Spider-Sense Tingling
3x Tragic Loss
3x Nice Try!
4x Fun and Games
4x First Class
Yes, every single character in your deck either has a worthwhile activated power or interacts with activated effects, and more than that, for those that don't already have one, Fun and Games grants an Activate power to all characters in play, yours and those of your opponents. Thankfully, with the swarm abilities of Multiple Man, you'll likely win any Activation war you get into, and Siryn will make an opponent think twice about even trying to get into such a battle.
Just in case you can't burn your opponent to death, though, you have that single copy of Strong Guy available, and when your whole board can Activate, Strong Guy can get big, fast.
The remainder of the effects you have are geared towards keeping yourself alive. Spider-Sense Tingling can keep some extra characters around - Multiple Men can be made invulnerable already, so making them evadable means your board can keep fair size, especially with Falls Edge helping you out every turn and an occasional First Class. The loss of Birthing Chamber hurts, but Empire State University and ESU Science Lab step up admirably - and ESU Science Lab really, REALLY likes Energize.
So, there you have it. Untested and unpolished, as all my decks are, but I hope you've enjoyed. The interactions between the two teams mean that you'll be gaining a not-insignificant amount of life while your opponent loses it slowly, and with a little fine-tuning, this could be a pretty potent deck. Not for tier 1 play, I suspect... but for annoying your friends? Hell yes.