Help on team building (MVC3)

Hey everyone I’m relatively new to these forums and fighting games in general. What are some things to consider when building a team? Up to now I’ve been using Deadpool (quick work)/Dante (Jam session)/ Akuma (Gohadoken). It’s been working fairly well, but I don’t understand the methods and “science” behind building an effective team and what key elements should be considered. Any help/advice would be awesome. Thanks!

Marvel vs Capcom 3/Game Elements/Character Selection - Shoryuken Wiki, Marvel vs. Capcom 3 Strategy and More!

That should provide you with some interesting reading material that should get you on the right path.
The most important thing you want to consider when creating a MvC3 team is synergy, that is, the strength of your team is greater than the sum of the team separately.

What that means for you is that instead of designing a team based around three characters you like, possibly with similar assist types, you want to build a team that functions well together as a whole.

An example of synergy at work could be Wesker (Samurai Edge) / Chun-Li (Lighting Legs) / Trish (Low Voltage)
In this example, Wesker plays the role of a battery, or someone who builds meter for the rest of the team. Chun-Li will be designated the rushdown position and Trish will be designated to spend the meter that Wesker (and probably Chun-Li) build, as well as provide keepaway against characters who rushdown better than Trish can. It’s not the best example but it’s what I came up with off the top of my head.

Wesker provides an OTG assist that both Chun-Li and Trish benefit from. Trish can use her Round Harvest hyper to lock the opposing fighter down and then switch out with Chun-Li. With Wesker’s OTG assist, Chun-Li can then create an unblockable situation on the opposing fighter with an instant overhead attack thanks to Trish’s Round Harvest hyper locking them down.
Chun-Li’s lightning legs assist provides a fast attack that can create pressure on the opposing player, and if the attack connects will give Wesker or Trish an opportunity to deal some damage without fear of reprisal.
Trish’s Low Voltage projectile can help build some pressure and to zone a bit. Wesker can use this assist to have Trish fire a projectile and then teleport to the other side of the other player, creating a situation that is much more difficult to deal with then if Wesker had teleported without the aid of Trish’s assist.

Picking characters with good assists can also help you link longer combos than if you didn’t use an assist. For example, Trish doesn’t have an OTG move but with the help of Wesker she can create much longer combos then she normally would have been able to.

Asides from character roles and proper assists, another thing to contemplate is your characters ability to hyper cancel into each other.
For example, if you DHC from Wesker to Chun-Li to Trish, you might get something like Phantom Dance -> Kikosho -> Max Voltage. However, it might be difficult to connect Chun-Li’s Kikosho hyper (or any of hers really) after Wesker’s, so you might consider moving Trish to the 2nd position for easier delayed hyper combos.

Those are just some things to think about to help you figure out how to build a proper team.
It can be extremely daunting, and I have personally spent a large chunk of time staring at the character select screen pondering the variables in building my team. Once you build a team that works well together you’re going to see your possibilities open dramatically.

Hope this helped!