- Super Hero Squad
- Silver Surfer / Dark Surfer (Norrin Radd) (First appearance as Dark Surfer)
- Lethal Legion
- Collector (Taneleer Tivan) (Mentioned)
- Galactus (Mentioned)
- Nova (Richard Rider) (Only in flashback)
- Captain Marvel (Mar-Vell) (Cameo)
- Adam Warlock
- Kree Soldiers
- Shi'ar Fleet (Mentioned)
- Empress Lilandra (Mentioned)
- Captain American (Steve Rogers) (Appears on a computer screen, TV, or hologram only)
Races and Species:
- Infinity Gauntlet
- Iron Man Armor
- Doctor Doom's Armor
- Factor Booster Gauntlet (First appearance)
- Silver Surfer's Surfboard
- Infinity Sword
- Falcon's Wings
Thanos completes his Infinity Stone collection and the Super Hero Squad faces him in a final showdown for the fate of the universe. However, when requesting backup from one of their own, they encounter a betrayal that changes everything.
- Title card's issue homage Silver Surfer (Vol. 3) #34
- In this episode, it is revealed that Adam Warlock was the imprisoned person in the Soul gem.
- Subsequent episodes have only been available on iTunes or, in Canada, Teletoon. In Australia this is the last episode of Series 2. Series 2 is Australia's Season 2.