Your latest fun team combination

Apocalypse/BRB/Lady Octopus
OML/Polaris/Emma3>4
Shang Chi/Darkveil/XFW

Have you tried using 5* Carnage with her?

Carbage generates new friendlies when you match or destroy them though, so he may be better.

Having recently ascended Eddie Brock Venom, the best pick-3 team I've found for him so far is probably 5* Kamala/EB Venom/4* Black Panther (ascended to 5). It takes a little getting going, and you're really playing with fire up agains the sea of Thor/Polaris teams you're going to face in the pick-3 environment, but if you can flood the board with enemy protect tiles for a couple turns and then fire Venom's green (that gets cheaper as the board floods with enemy protects), it will generally cascade into a truly comical amount of damage.

I've run him between both of the carnages and ascended Kraven, alongside 5* Strange and Apocalypse (eye of agomatto now generates a yellow every time it removes a special), with Vulture, There are a decent number of teams that are mechanically ok, but nothing hits like that first team.

Since my Korg support is too low level I use Avengers Tower instead. I also use Stepford support on Emma. A very useful and quick team.

Still not entirely sure what she does, but I was running (5* Agatha 2/2/3 no levels)/nightcrawler (4* ascended to 5)/Sersi for awhile to make a crit spam team since they can control the board on 3 colors. I’m sure Agatha’s blue does more than add a couple tiles of the chosen color but I can’t be bothered to screenshot the power and zoom in to see what that is. Anyway it works pretty well for hitting a match-5 on most turns, and Sersi’s countdowns hit pretty hard when they go off.

Add prowler

Shang-Chi with 5 star Agatha and either Namor is absolutely ridiculous. I prefer the 3 star version because 5 cost crit creation and 125% of match damage in bottom rows being dealt to a random enemy is just so good, especially if you run Krakoa on him as support, because 2 black and green AP boosts guarantee you a crit creation first turn. If you run 2 blue and purple AP boosts you're guaranteed to be able to get Agatha's 3 cost blue off turn one as well unless there is somehow not a single blue match to be gained.

5 star Namor is also incredible with that 45% increase to cascade match damage synergizing with Agatha's increase to match damage with each match and Shang-Chi's own personal match damage increase, especially since the active is only 6 and makes cascades more likely. I don't have him at 13 covers yet, so this is theory on my part, but if you use Atlantis as a support and a single green and black AP boost there's a good chance you'll be able to cast it on turn one, and it makes your match 5's grant a green, black and purple AP as well, which is great for Shang-Chi, and if you run Snack Cart on Agatha you gain a purple every time you use on of your abilities - so that's two bonus purple if use you use them to make a match 5. Put Chimichanga on Shang-Chi and you've got good odds to grab 2 bonus purple and red AP with matches in their color, casts of Agatha's blue creating a match 5 opportunity in purple with the 4-5 purple tiles you create per cast of it can end up giving you 4 bonus purple with one ability cast, 5 if you use it twice, so you're gaining over a full cast of Shang-Chi's purple in one turn easy. Or you can spam it creating blue tiles to keep firing it until you've made 6 matches and gain 1 purple on every cast and 1 purple on ever match 5 you get from spamming it, or grab 3 purple AP with 2 casts on green and a match 5 with any luck, plus 6 green minimum from the match 5, allowing 2 casts of Namor's cascade creating green ability at least if you started with at least 6 green from boosts and Atlantis, and a generation of 5 purple even without any matches or tiles getting destroyed by match 4's that might occur in the process. With any luck at all you should only ever need to let the enemy have one turn max- as long as there is a blue match on the board you're set to go on your second turn. You could also gamble on getting at least one blue and remaining under 6 matches from cascades, use 2 blue and purple AP boosts, a green and black AP boost or two, and start the game with a cast of the board shake green if you get the 5 green at start from Atlantis, in which case you'll be up to 4 purple on turn one regardless of which color you plan to focus.

You could even swap Quantum Realm onto Shang-Chi instead of Chimichanga, giving you good odds at starting with 5 purple. So with the 2 blue, purple, and green from standard AP boosts, and, if you're lucky, the 5 purple and green AP from supports that leaves you with 7 purple, 7 green and 2 blue at start. One cast of SC's crit creation will get you at least one cast of Agatha's blue, and leave you with at least one purple, then Agatha's blue cast will leave you with at least 2 purple and the option to use the green board shake for at least 1 more purple, so 3 minimum, regardless of the color you choose for Agatha's blue even before the AP that might be gained off the casts active effects on the board or lucky match 5's. I'd choose blue for Agatha's cast, hopefully getting you a match in blue to use it again and go up to 3 purple, shifting the board towards blue by 4 and possibly 1 extra purple as long as the snack tile isn't created on an already present purple, each time. Repeat the process til you hit 6 matches (you can always swap to red or purple or green when advantageous, especially if you get at least 6 blue before you hit 6 matches), charging up at least one purple every cast. With any luck by the time you've reached the point where you can't keep spam casting the blue, or make a match 5 naturally, you'll have enough purple for crit creation again, maybe even enough red to cast SC's destroy 5, and create a match 5, gaining 2 bonus purple and a green. If all goes well, you can keep alternating between Agatha's blue and SC's red and purple as advantageous, gaining bonus purple every cast and bonus green and purple on every match 5, until you've hit the six matches that trigger the swap and run out of available match 5's. At that point you can start dropping Namor's board shake into rotation with SC's abilities, til you run out of AP and match 5 options. Finally you can cast Agatha's blue if you have the 6 for it and return it to the 3 cast option once you reach 9 blue and can cast the 3 cost version at least once, but you're probably better served saving that til you've run out of other options or stored up at least 12 blue as you don't want to waste available match 5's or opportunities for using SC's abilities to create good matches or cascade matches from Namor's green to fill up your 6 matches before you can get at least a couple uses of the 3 cast version out.

So theoretically you can ramp up to winfinite with insane damage on turn one, and you've got a really good chance at doing it as soon as you have 6 blue AP, as long as you can hit that on the first few turns.