A lot of people are objecting to this on grounds that DC’s characters hopelessly overpower MK’s characters. This is obviously not a real problem, since it’s a crossover between two universes and they can make the rules however the fuck they want.
What I do find objectionable is that the spirit of some of DC’s characters, even the darker ones, is morally incompatible with the spirit of Mortal Kombat. Their mythologies simply don’t mix. MK is steeped in violence, bloodshed, and gratuitous killing… DC, not so much.
If Superman starts dishing out fatalities, I might actually have to write my first ever angry fanboy letter to DC Comics. You don’t shit on a cultural icon like that.