8: Pentagon Jr.
While Chris Jericho may have dressed up as Pentagon Jr., the two men have never faced off inside the squared circle.
Jericho grabbed the headlines when he swapped places with Pentagon after his match with Kenny Omega at All In, proceeding to lay out the IWGP Heavyweight Champion, but in the eyes of many fans, he missed an opportunity there.
Rumours of Jericho signing with Impact Wrestling have been circulating for months, and having Jericho attack Pentagon would have added fuel to that fire in a way that only Chris Jericho can.
Regardless of whether Jericho signs with Impact or not, though, this match could still happen at some point in the future.
While it could easily happen at an event like All in 2, it could also take place if Pentagon signed with the WWE, which has also been something that has been rumoured for some time now.