2. Chris Jericho

Chris Jericho is one of the biggest superstars in all of Pro Wrestling. He was a WCW original who gained a lot of success and popularity there. He came to WWE and 'broke the walls down' there as well. He has had multiple runs with the WWE and has been a master of gimmick changes and character work. But most of his work during the mid 2000's and early 2010's has been on the blue brand. He was Smackdown's top heel for years and gave us some of his best matches as part of the blue brand.
Jericho is currently New Japan Pro Wrestling's IWGP Intercontinental Champion. That might cause a problem but probably won't as Jericho appeared on Raw 25 fresh off a feud with Kenny Omega in New Japan. Hell, he might even bring the IWGP Intercontinental Championship with him to Smackdown Live. Jericho's relationship with WWE has always been good and the door for his return will always be open. Whether Vince allows the New Japan star to make an appearance as IWGP Intercontinental Champion is yet to be seen.
Look who just shut down all of Tony Khan's critics! More HERE.
The most ironic fact here is Jericho is a part of the Smackdown roster as of now. He was put off screen back in 2017 as part of an angle with Kevin Owens. He might just return to the ring at Smackdown 1000 for all we know. Whatever might happen, it is for sure that everyone involved will be glad to see Y2J back with WWE.