After agreeing in peace with the Highfather, Darkseid hasn't given up in his goal, which is to find the Anti-Life Equation and rule everything. Darkseid will begin to break the Highfather's promise here where he will decide to continue looking for the Anti-Life Equation, his lifetime goal to achieve his ultimate goal, to reimagine the universe in his own imagination, where everything and everyone lives in a red and hell-looking area like Apokolips.

You could use a dark, almost scary, and menacing voice for Darkseid or his JLU voice. Or you could do whatever fits him.