User blog comment:Gon10/Kuchiki Byakuya´s Bankai/@comment-5551986-20130623085502/@comment-11051098-20130623124615

Mayuri will definitely study a medallion if he gets his hands on one, I hope he can find out how to release a stolen Bankai from a medallion. I think the medallions are made to both be able to steal a Bankai and to release it again.

The question is - Yhwach is probably the one or one of those behind the creation of the medallions, but how did he manage to make a device to steal a Bankai? I'd imagine he would need alot of knowledge about how a Bankai works to be able to make a devide that could steal one.