Undertaker's going to be retiring in the next 2-3 years. You think you can get signed by WWE, make yourself relevant, and get to a level to be considered as a WM opponent for the guy in that time? Good luck to you I say. But that's a near impossible task for you.
In short, if you ever, EEEEEEEEEEEEEEEEVER face the Undertaker, I'll give you millions of dollars.