Fight Brock Lesnar himself

Since his return back in 2017, Kurt Angle has been pretty much undefeated. He picked up wins at TLC and Survivor Series before defeating Triple H and Stephanie McMahon at Wrestlemania (this stat has actually been fudged just a wee bit; Angle technically lost at the Greatest Royal Rumble, but that doesn’t really count since it’s been all but forgotten). He is on a roll.
He and Lesnar used to face each other fifteen years ago. They had a vicious feud over the WWE Championship, and Brock Lesnar won after doing a shooting star headbutt at Wrestlemania. But since Kurt’s been picking up wins left and right, why not make himself the number one contender?
He’s beaten Brock a couple of times in the past, so he has a greater chance than most of beating the Beast for the Universal Championship. And deep down, Brock probably respects Angle. So that’s that.
If Kurt wins, he could vacate the title and have some tournament for it, or he could hold it and never book any title defenses for himself so he can beat Bruno Sammartino’s record. But if that’s what it takes to beat Lesnar, then so be it.
