Injustice 2
75 Achievements
153-209h
I Didn't Do It
Brainiac must defeat any opponent with the final hit coming from Beta Strike
5.0%
How to unlock the I Didn't Do It achievement in Injustice 2 - Definitive Guide
Now, enter any match with Brainiac (For ease, I prefer either a vs match against a second controller, or a single fight against an AI opponent on very easy). Get their health down to just a sliver, then use Brainiac's Character ability (B) to launch low damage missiles (Beta Strikes) at your opponent. When they go down from this attack, you will get the achievement.
Otherwise, great guide
Beta Strike is performed by pressing . I think it becomes more powerful if you hold the button longer, but all you need to do is KO an opponent with this move.
Set up either a versus with 2 controllers or a Very Easy Single Fight. Pick Brainiac and any other opponent, chip their health down to as low as possible without winning and then press to perform this move. The trophy should unlock after.
Get your opponent to 5% of health left and press to KO. It's really, really easy.
Use missile projectiles by hitting to finish off your enemy. Cannot be done until you finish Story Mode and unlock Brainiac
To have a chance to use Brainiac, first you need to beat the Story Mode at any difficulty. Once you have him unlocked select any mode you like, select Brainiac as your main character and any as your rival. Select any map and start the match.
Once the match starts, keep hitting your rival until he has around 5% of health left in his red bar. At this point, using Brainiac stay middle-close to your rival and press to throw the Beta Strike. Once your rival is defeated with this strike, the match will end showing the trophy in the screen.
Video: https://www.youtube.com/watch?v=BB9IAJo9m8M. (Credits: Trophy Germany)
Use missile projectiles by hitting to finish off your enemy. Cannot be done until you finish Story Mode and unlock Brainiac