While most of the 36+ characters unlock naturally through the story mode, four "secret" characters require completing specific trials:
: Complete the final trial in the Psi Rift (after Chapter 7). MARVEL-ULTIMATE-ALLIANCE-3-The-Black-Order-NSP-...
: These are powerful combined moves performed by two heroes simultaneously. They are critical for depleting "Stagger Bars" on bosses. Characters with elemental traits like burn, freeze, or shock tend to synergize with the widest range of team members. While most of the 36+ characters unlock naturally
: Complete the final trial in the Gamma Rift (after Chapter 5). Characters with elemental traits like burn, freeze, or
The main campaign typically takes about to complete and follows these primary chapters: Guarding the Galaxy : Intro mission on a Kree ship.
: Complete the final trial in the Lambda Rift (after finishing the story).
: Complete the final trial in the Sigma Rift (after finishing the story).