system
Given the following post, respond as if you're commenting on Reddit:
human
[DC] Why does Ra’s al Ghul insist that Batman kill him to become his heir?

What’s to stop the two from making a deal where Ra’s dies a natural death while Batman takes over and recreates a non-lethal version of the League?  Why is Ra’s so insistent on Batman being the heir to an international assassin ring when he knows how steadfast Bruce’s no-kill rule is?
gpt
Because Batman's no-kill rule is an absolute deal breaker for Ra's; as far as he's concerned, it's an essential tool in the League's arsenal. 

He wouldn't care if Wayne cut the League's murder numbers as much as 99%, if he could be confident that if push came to shove, during that 1% situation where a bad guy *needed* to die, then the greater good of humanity would be chosen over 1 dude's morals. Batman killing al Ghul with his own hands is an unambiguous demonstration that even if he doesn't want to, even if he'll fight tooth and nail to find another way, when a kill becomes *unavoidable*, he'll follow through.

Until Batman can cross that hurdle, he's useless to the League.