How would Superman react if Batman died? by Christian Mueth
Answer by Christian Mueth:
Superman would be absolutely crushed, and disbelieving. Take the time that Batman died during Final Crisis, for example:
Superman was absolutely heartbroken. And— Batman eventually came back to life in this story (“Return of Bruce Wayne”), so we didn’t even get to see the full extent of Superman going through the grieving process.
I think that this quote from Superman says it all:
“You’ll outlive all of us, Bruce. You’re too stubborn to die.”