User blog comment:B214/Volume 22 spoilers/@comment-185.112.105.215-20161011161249/@comment-9595671-20161013014113

It was more behind the lines of Hades likely thinking its a "only works once" type of plan. When he gave Cao Cao's team Samael, no one saw it coming, but now people know Hades has it.

Even if Sirzechs and Azazel aren't there anymore to hold the threat they made, I bet they told the Greek pantheon about it just in case something came up. Poseidon's likely got that job now.