In the Justice League Animated Series, one alternate universe had Lex Luthor kill that universe's Flash.
So Superman killed Luthor. And he didn't feel bad at all.
A few years later, the Justice League of that universe became the Justice Lords - tyrants who control the world based on their whims and fancy.
In any organisation, you have the leaders, like Superman, and then you have the conscience of the group like The Flash.
You take out the leader, and the team will be like headless chickens. You take out the conscience of the team, and you change the team altogether.
And the conscience, the soul of the team - any team - need not even play a significant role in the whole system. Minor characters, some of them, or secondary. Like Marge Simpson - not that funny, but take her out and there is no The Simpsons.
When writing scripts, understand the dynamics of the relationships between the characters as they influence each other profoundly. No man is an island.
