well... It could work based on the move that triggers the brutality animation.

So there would be one for Batman where bats would paralyse the opponent in fear on the floor. One where Superman punches someone off the screen. One where Supergirl drives someone into the ground. One where Wonder Woman just keeps the lasso on the opponent as they collapse, exhausted and start muttering truths.

Also there would be ones where the Harley's hyenas just tear someone apart, one where you watch the Joker toast marshmallows on a flaming body, One where there is a hole in the face from Deadshot's gun. (Erron Black style)

Maybe.

Yea that's be cool if done right.

...I'd be on board with this. Great idea.

Some ideas

Joker handshake special from the MK/DC crossover should return, and leave the opponent a fried skeleton. Right out of the 1989 Batman movie. The opponent's clothes and armor should remain however, and be fried as well.

Joker should use his smilex gas for a special move, and for the brutality, make them laugh to death. The camera would zoom in on them when they start laughing, similarly to Johnny Cage's eye poppin' brutality, and when they drop dead, the camera shows us the big smile on their face.

Wonder Woman's supermove leaves her opponent alive but stuck in the ground.

The Flash grabs his opponent and takes them for a ride at full speed. That could be his supermove, which'd lead to this brutality when done at the end of the match.