Time Gem: Makes all of his normal attacks faster.

Power Gem: Creates an afterimage that adds two additional hits to all of his normals. Doesn't affect Special Moves or Infinity Specials.

Power Gem: Functions similarly to Morrigan's Astral Vision in Darkstalkers. In that it creates a mirror image that shoots behind the opponent and mimics what Spider-Man does. It doesn't do any damage, however.

Space Gem: Creates a Force Field around him, that stays active for about 7 seconds.
During this time, Magneto is impervious to most attacks, including Infinity Specials, and cannot be grabbed. He can however, still be hit by Shuma-Gorath's Chaos Dimension.
Hitting the Force Field will shave off some time from the power up's duration.

Space Gem: Super Amour that's stronger than the default variant. Juggernaut glows grey for the duration of the gem's power. Like Magneto, getting hit shortens the duration of the power up. Consecutive hits break armour faster, and he still takes normal damage from grabs.

Soul Gem: All of Iron Man's normal attacks will steal super meter on hit.

Power Gem: Psylocke creates two clones of herself. One stays behind her at all times, and the other in front. They mimic all of her attacks, including Special Moves and Infinity Specials.
Psy Blast and Kouchou Gakure remain the same however. The clones will simply mimic her movements.

Power Gem: Captain America's Stars & Stripes and Charging Star will do additional hits, akin to the Super Move versions in later games. Also causes his shield to act like a Boomerang: instead of bouncing off the opponent and falling, it will always return to the Captain's hand.

Time Gem: All of Shuma-Gorath's normal attacks turn the opponent into stone. Hitting the petrified opponent will cause them to break free. Also applies to the Special Moves Mystic Smash and Devitilization. Using Chaos Dimension during this time will immediately end the power up's timer.

Reality Gem: Makes Blackheart completely invisible for the duration of the power up.

• You can be certain that you've activated a unique ability when "SP" shows up after the respective power up's name, as shown below;
  
  
  
  
• When you have multiple gems, you can press Start to scroll through them;
  
• Any normal effect the gems have, such as boosted strength, still applies with the unique effects;
  
• Anita, Dr. Doom and Thanos do not have any unique gem abilities.