When each of them never really knew... what hit them...

That was the right amount of food he could eat, while Bruce was waiting for the right moment.

They might not have killed him if they didn't want to, but they did...

At that moment, he learned from some informants, whether he had died, or not, that Two Face, Harley Quinzel, Joker, Crocodile, Poison Ivy, and the Riddler were plotting an ambush to find and kidnap him.

He did it, anticipating, before them.

What was the gamble that they would possibly kill him, he knew they would if he had the chance, and who was he, to deny an opportunity...