Relating Avengers precisely to League characters
I was just so bored...
Ironman to - 
Passive Focused Disruption: Summary, after 3 hits from any ability, the enemy takes a burst of true damage.
Q Explosive Ion: Fire out an Ion bomb. Reactivating the Ion bomb explodes it in two separate directions. W Charged Pulsefire: Ironman fires a mini-laser at targeted direction from his hand. Second later, laser fires again in increased damage. E EMG (Electromagnetic Gravitation) Cannon: Ironman fires a bomb on the ground that explodes; silencing, dealing damage and knockups its target in the air. R Unibeam: A focused beam channeling at cursor's direction, dealing damage to those on its path.
_Captain America _ to 
Passive Hold the line: Captain America's attack speed increases due scaling of missing health.
Q Shield Toss: Cap throws his shield, enemies hit by the shield deal damage and are slows. Picking up the shield reduces cooldown. W Combatant: Lifesteal increases based on missing hp. In addition, increasing attack speed E Heavy Toll: Cap's next attack deals true damage to the enemy and himself. If next attack kills target, hp is refunded. R Iron Will: Cap cancels all crowd control effects and gains movement speed, resistance and damage attacking the enemies.
Captain America 2 to 
Passive Challenging strike: Captain America seeks out his foe's weakness. If he succeeds, he gains bonus stats.
Q Dash: Cap dashes at the enemy striking those near. If strikes an enemy, cooldown reduces. W Shield Parry: Cap blocks all attacks. If hit by crowd control, enemies in direction are stunned. E Pressure combatant: Cap's next two attacks gain attack speed. First attack slows and second critically hits. R Heroic Moment: Cap spots four weak points on target. If target is killed or all four spots been hit, creates a healing field for allies.
Thor to 
Passive Thunderous strikes: Thor's attacks cause enemies to be electrocuted, slowly dealing damage to them. After 5 attacks, Thor gains attack damage.
Q Broad Swing: Thor swings his axe around him. Thor heals by those he strikes around him W heavy Blow: Thor's next attack electrocutes the enemy while also slowing them. Cooldown refreshed if it kills them. E Homing call: Thor throws his axe a small distant in front of him and calls it back. Enemies caught in the direction get pulls in from his axe to him. R Stormbreaker Call: Thor goes into the air and strikes Stormbreaker down on his foes dealing true damage ratio of enemy missing hp. If it kills the enemy, cooldown resets.
Thor 2 to 
Passive Worthy Empowerment: Thor charges his weapon. Stacks up 3 times and spends one stack per auto.
Q Godly power: Thor attacks in a series of three strikes. Two strikes apply damage and third strikes the ground, knocking those in its radius. W Lighting strike: Thor strikes himself with lighting, anyone near him is stunned and applied damage. E: Freeflow: Thor dashes to designation. Shielding himself in the process. R Call of Stormbreaker: Thor's weapon Mjolnir is changed for Stormbreaker. Giving Thor more damage. A second cast fires a burst of lighting damaging those in front of him. Damage scales through enemy missing health.
Hulk to 
Passive Anger: Hulk's attacks give him life steal.
Q Smash: Hulk smashes his foe applying a stack of damage and life steal upon who he kills dependent on target. W Hulk Scream: Hulk screams at his target, fear at his target applies a slow and reduces attack speed. E Hulk Quake: Hulk slams the ground and shakes, reducing enemies in radius armor and applies damage. R RAGE: Hulk enters a rage state. He gains health regen, damage and Smash cooldown decreases.
Black Widow to 
Passive S.H.I.E.L.D agent: Black Widow gains movement speed towards enemy players.
Q Tumble: Widow rolls on the ground direction. Next shot is an empowered stinger shot. W Stingers: Widow fires a stinger. Stingers at third attack stack does bonus damage. E EMP Net: Widow fires a powerful electric net at the enemy; pushing them back and slowing them. If hit by a wall, they are stunned. R Avenger: Widow gains damage, movement speed and Tumble allows her to turn invisible. Killing enemies reset the cooldown.
Hawkeye to 
Passive Clean shot: Each kill, temporarily increases attack speed.
Q Empowered Arrow: Hawkeye charges an arrow increasing range and damage dependent on charge time. W S.H.I.E.L.D. Quiver: Hawkeye applies an arrow stack per attack. Attacking those marked with ability increases damage. E Sticky Volley: Hawkeye fires a volley of arrows in the sky that rain down on enemies, slowing them and reducing healing. R Electromagnetic Arrow: Hawkeye fires an electric arrow that snares his target. The arrow connects to those nearby and snares them as well.
Im sorry, i was just so bored...