[Western Crossover] Can the Old Bat ____?

A sad story where everyone else is reborn, but I transmigrate.

Bruce Wayne, AKA Batman, transmigrates. He becomes Illumi Zoldyck, eldest son of a family of assassins, and makes a name for himself under that identity. Eventually, he gets his wish and dies at the hands of his beloved younger brother, then transmigrates back. At this point, his second son has just been killed by the Joker.

Bruce: ...I can't kill the Joker, but... I'll put him through the same torture he put my son through.

His eldest, second, third, and fourth sons, all reborn: ...Why aren't you following the script!?!?

Superman, reborn: (furious) Why didn't you kill the Joker?

Bruce: (showing Superman the Joker) Isn't this better?

Superman: ...Yeah.

When the Batfamily has one of their loving "talks," Bruce gets ganged up on by all four sons and is so proud he could almost cry. The little moths have grown up and can beat me up now. It's so... exciting!

The younger brothers who came to this world to find their big brother: ...Well, this is a sudden turn of events. My brother has sons, and so many of them!?... So that means I have adorable nephews I can play with (and rough up)!? Big brother, you're the best!

And so Gotham's villains sadly discover that they can no longer have fun playing with Batman the way they used to.

Who could handle Batman killing the hostage himself just to beat them up!

The Hunter x Hunter part is brief. Most of the story is in the DC universe. For now, the reborn characters are the four Batfamily boys and the big blue guy. There may be more depending on how the story goes. The pairings are up to fate. We'll see where things lead.

Theme: A rational discussion about killing and not killing