Hey, sign me up! Not really a Sheamus fan but I can't deny that meshes up well with big/bigger guys, so him against Lesnar definitely has the potential for a fantastic physical brawling match. And there are some similarities between the two.
As they shouldn't, he hasn't earned it. He took a dump on the face of the best talent on the roster and said "fuck you, I don't have to do SHIT but show up and pin you after you carry the entire program". Disrespect begets disrespect. Undertaker is a selfish, arrogant, broken down old has been who can't give it up, who doesn't give one shit about the next generation of stars and helping the company that made him thrive. It's always all about him.
Brock Lesnar vs Sheamus would be one hell of a feud. These two facing off against one another would be an all-out brawl. With Sheamus and Brock Lesnar's ability to intensify a feud when needed to, it would make for a very compelling feud. I would love to see it.