First, play any Solo Infinity Trial. For example, play Hulk's Solo trial. Make sure the character you select (Hulk for this example) is in the second, third, or fourth character slot. Start the trial and get defeated. After failing, select "Quit" and go to the menu, then go to Hero Select to see there is a duplicate character on your team. This glitch causes the first slot to be replaced by the Solo Trial hero. To duplicate again, free up the first slot. Select the first slot (Hulk), then select a character on the roster that is already on your team. If you select a character that is not on your team, you will lose the duplicate character. Next, select a character that is already on your team to switch places. You can now repeat the Solo Trial, fail, exit to Hero Select, and swap again so the first slot is free. Repeat this process one more time to have four of the same hero. Note: Use chapter select and all four duplicate heroes can enter Story mode. Otherwise, you have to use them in Infinity mode only. This glitch is very helpful for grinding levels. You can earn x4 XP and rewards using this glitch, including on easy trials.
Successfully complete the indicated task to unlock the corresponding character:
Elektra: Successfully complete Infinity Rift Gamma – Ultimate: Bad Business Lv. 30. This rift is first available in Chapter 3.
Loki: Successfully complete Infinity Rift Sigma – Boss Wave: Defeat Ebony Maw and four Lv. 45 Bosses. This rift is first available in Chapter 9. Note: Loki is only available after completing the game on the "Mighty" difficulty. To unlock him, you must fight all five members of the Black Order in a trial, one-at-a-time, which is fairly challenging.
Magneto: Successfully complete Infinity Rift Psi – Boss Wave: Defeat Klaw and two Lv. 38 Bosses. This rift is first available in Chapter 5.
Thanos: Successfully complete Infinity Rift Lambda – Ultimate: The Black Order Lv. 65. This rift is available after completing Chapter 10. Note: To unlock him, reach Chapter 10 on the Hard difficulty and complete many of the trials in the final rift. You must defeat all five members of the Black Order, all at the same time, to unlock him.
Successfully complete the game on the Mighty difficulty to unlock the Superior difficulty.
Successfully complete the game on the Superior difficulty to unlock the Ultimate difficulty.
Lambda rift trials
Successfully complete the game on the Mighty difficulty to unlock the Lambda rift trials.
Omega rift trials
Successfully complete the game on the Superior difficulty to unlock the Omega rift trials.
Fifth ability rank slots
Successfully complete the game on the Superior difficulty to unlock the fifth ability rank slots.
Fourth ISO-8 slot
Unlock all six special nodes in the Alliance Enhancement grid to unlock the fourth ISO-8 slot.
Team combo bonuses
Place the indicated characters on a team to get the corresponding bonus:
Total Biggest Boost Team: Wolverine, Gamora, Psylocke, Elektra
Total Bonus: +28%
Strength Boost Team: Wolverine, Gamora, Psylocke, Deadpool
Total Bonus: +27%
Durability Boost Team: Iron Fist, Luke Cage, Daredevil, Doctor Strange
Total Bonus: +17%
Energy Boost Team: Black Widow, Falcon, Hawkeye, Captain America
Total Bonus: +18%
Synergy attacks are special skills that you can chain-together with two characters. You can initiate one instantly by holding RT and selecting a high-lighted attack, or you can press A when an ally is performing an attack you can synergize with. The game does not tell you all synergy attacks. The following is a list of all synergy attack combos:
Calamity: Whirlwind + Bash. This generates an exploding tornado that deals damage to enemies in the area.
Catalyst: Bash + Burn. This blows enemies away at a greater range.
Coalesce: Burn + Whirlwind. This generates a burning tornado.
Crash: Barrage + Area Assault. This generates intermittent shockwaves that deal damage to enemies in the area.
Elemental Barrage: Barrage / Area Assault + Whirlwind / Burn. This send a tornado or elemental slashes to slice through the enemy.
Eruption: Beam + Explosive. This causes any beam attack to explode with more power than usual.
Mega Blast: Slam + Explosive. This launches a large explosion made-up of smaller explosions.
Reflect: Beam + Safeguard / Area Assault. This shoots a beam that scatters in all directions and deals damage.
Resonant Blast: Beam + Beam. This launches a huge blast that generates a sphere of energy at the point of impact, dealing damage to nearby enemies.
Ricochet: Rapid-Fire + Safeguard / Area Assault / Whirlwind. This shoots a series of rapid-fire projectiles that scatter in all directions and deals damage.
Scatter Shot: Rapid-Fire + Rapid-Fire. This causes projectiles from a rapid-fire attack to explode on impact, dealing area-of-effect damage.
Shockwave: Bash + Bash. This causes a powerful shockwave with expanded range.
Surge: Launch + Launch. This launches a huge shockwave that throws enemies in the area into the air.
Tremor: Slam + Slam: This causes a powerful ground quake that damages enemies in the center of the blast, and causes all enemies on-screen to stumble.