Would Fail: the Undertaker

We love the Undertaker with an adoration that borders on worship. He is one of the greatest performers to ever enter a wrestling ring, and his long undefeated streak at Wrestlemania is a testament to that fact.
However, in spite of using MMA inspired moves in the ring, we don't think he would do well to transition. For one thing, his advanced age is a great hindrance. He just doesn't have the conditioning to go for fifteen minutes with a guy in his twenties or thirties.
Also, Taker is a combat sports hobbyist, at best. He has little to no actual combat sports training and would have to rely on his--admittedly impressive--physical prowess to succeed. Taker would also need to cut nearly forty pounds of weight to enter the heavyweight division, and that just wouldn't be healthy.
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