Mine's Psylocke, she is very underrated, and I have high win rate with her.
This is a continuation of my Juggernaut character concept.
Team-Up 1: Magnetic Allegiance
Anchor: Magneto
Anchor Boost: +125 max health.
Receiver: Juggernaut
Team-Up Ability: Force Pull
Juggernaut releases a magnetic pulse that pulls debris within a large nearby radius to him. If there is an obstacle in the way, the debris will be halted and will drop to the ground upon collision with it.
Has a 20m radius and a 25s cooldown.
Team-Up 2: X-Rivalry
Anchor: Juggernaut
Anchor Boost: 5% damage reduction.
Receivers: Wolverine, Storm, Magik, & Psylocke
Note: I made this one for fun. Don't take this particular concept too seriously.
Team-Up Ability 1: Furious Uplift
Wolverine stomps the ground to cause a piece of debris to pop out. He then stabs his claws into the debris and holds it above his head, waiting to throw it at the opponents.
All of these abilities deal 100 damage and have a cooldown of 20s. The projectiles travel at a speed of 8 m/s.
Team-Up Ability 2: Stormy Uplift
Storm raises her fist to pull a chunk of debris out of the ground below here, waiting to throw it at the opponents.
Team-Up Ability 3: Limbo Uplift
Magik summons a limbo portal in which a demon climbs out with a piece of debris, waiting to throw it at the opponents.
Team-Up Ability 4: Psionic Uplift
Psylocke throws a swarm of shurikens at the ground in front of her and retracts them to pull out a chunk of debris, soon waiting to throw it at the opponent's.
I kinda went crazy with the last one, but I think the first one is fairly balanced.
Let me know if you have any thoughts in the replies!
I main Psylocke.
She's gotta great design, is good at long range and short range, and is just fun to play in general.