We know the person has been using a "chain". There's only 2 people that are known for using chain as signature weapon. Cena and his rapper chain. Obviously, it's not him.
The other person known for using a signature chain is...
Dudleys have history with Big Cass/Enzo when they lost to them in No #1 contenders tag titles tournament. I'm probably wrong and it will turn out to either be Cass, Enzo or someone that won't make any logic at all.