- Thor 🢒 (First appearance chronologically)
- Loki (First appearance chronologically)
- Odin (First appearance chronologically)
- The Leader (Samuel Sterns) / Leader the New All-Father
- Leader the New All-Father
- Frost Giants
- Gamma Frost Giants
Races and Species:
Hulk follows Leader back in time to the Viking Age and teams up with young Thor and Loki to keep Leader from taking the throne from Odin during his Odinsleep. In the present, the Agents of S.M.A.S.H. fight to stop "All Father" Leader from taking over the planet with Thor and Loki in his services as well as an army of gamma-powered Frost Giants.
- This episode's title is a reference to Days of Future Past storyline.
- The seen where Hulk swings Loki is a reference to how Hulk defeated Loki in Marvel's The Avengers.