Injustice 2

To get all Story Modes trophies you need to complete all 12 chapters while playing with different characters across 76 total fights. To make this step easier it’s strongly recommended you play on Very Easy. Do not expect a walk in the part even on this difficulty, some rivals are challenging, specially the later ones and may take you more than a couple of tries to beat them. Spamming or and sometimes can end the match faster, but there are enemies that you need to try different moves, so play wisely facing these rivals and change your strategy if you’re having troubles with any of them.

Also, once you beat the main story, after completing chapter 11, you need to replay some chapters playing with the other fighter you didn’t use in your first walkthrough and complete the bonus chapter (12). You can check which player you need to use this time if you browse through the chapter select screen. The grey ones are the characters you want to use.

Also it’s very important to take note that completing the Story Mode on any difficulty will unlock Brainiac and he is needed to unlock some trophies.

Here is the list of chapters and all alternate paths:

Batman:
1.1 Godfall
1.2 Not Like This
1.3 The Problem With Truth And Justice
1.4 A Break In The Family

Harley Quinn:
2.1 The Girl Who Laughs
2.2 Face Your Fears
2.3 Mad Love
2.4 Girl Meets Green

Green Arrow & Black Canary:
3.1 The Brave And The Bold
3.2 Venomous
3.3 A Fateful Warning
3.4 The Society Rises

Flash:
4.1 Invasion!
4.2 It’s Just Business
4.3 Future Shock
4.4 The Lantern Returns

Green Lantern:
5.1 Sea Of Troubles
5.2 Hunter, Hunted
5.3 Breaking Bane
5.4 Rage Of The Red Lantern

Blue Beetle & Firestorm:
6.1 Assault On Stryker’s Island
6.2 The Prodigal Son
6.3 Amateur Hour’s Over
6.4 The Nuclear Option

Cyborg & Catwoman:
7.1 Breaking And Entering
7.2 Gotham City Sirens
7.3 Bogeys In The Batcave
7.4 Hacking Brother Eye ( Half Way There)

Wonder Woman:
8.1 Goddess Of War
8.2 You’re No Oracle
8.3 Worst Fears
8.4 The Peace You Deserve

Supergirl:
9.1 Last Hope of Krypton
9.2 Whose Son Are You?
9.3 Thunder And Lies
9.4 This Isn’t Who We Are

Aquaman & Black Adam:
10.1 Three Kings
10.2 Broken Arrow
10.3 Black And Blue
10.4 You’re No King

Batman & Superman
11.1 The World’s Finest
11.2 Cracking The Code
11.3 Lord Of Order
11.4 Revenge Of The Last Son (only Superman)
11.5 Saving The World (only Batman) ( Who's Next?)

Batman & Superman (Bonus Chapter):
12.1 The Choice
12.2 Absolute Justice (only Batman)
12.3 Man Who Fights God (only Batman)
12.4 Your War is Over (only Batman)
12.5 Circle Of Trust (only Batman)
12.6 Absolute Justice Credits (only Batman)
12.7 Absolute Power (only Superman)
12.8 Fastest Traitor Alive (only Superman)
12.9 The House Of El (only Superman)
12.10 Knightfall (only Superman)
12.11 Absolute Power Credits (only Superman)