With The Undertaker and A.J. Styles set to collide in their Boneyard Match at WrestleMania in just a few days' time, the WWE universe has been combing through the recent promos the two men have been delivering to try to decipher what that match might entail.

One statement that The Deadman made on RAW this past week fueled massive speculation when he threatened A.J. Styles with an "Unholy Trinity," a phrase he's never used before. The internet has been trying to figure out ever since just who, or what, The Undertaker's Unholy Trinity might be. Some believe it might reference a stable, possibly consisting of Kane and his wife, Michelle McCool. It wouldn't be out of the question to see Kane show up to interfere in The Undertaker's match. It seems a little more farfetched to involve his wife Michelle in a men's singles match, but since Undertaker mentioned the similarity between her Faith Break finisher and A.J. Styles' Styles Clash in the same promo, that connection does also exist.

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However, some believe that The Undertaker's Unholy Trinity may have a more hardcore inspiration. Mick Foley infamously performed under three different personas throughout his wrestling career. The first was Cactus Jack, a wanted outlaw from the west who wore leopard skin pants and had a penchant for elbow dropping off of the ring apron onto his unsuspecting victims. This was Foley's first major persona and the one he utilized in his WCW and ECW days.

When he made it to WWE, Foley changed up his gimmick by introducing Mankind. Mankind was no less of a maniac than Cactus Jack, but had a brown leather mask strapped across his face and wrestled in a bedraggled button-up shirt. Foley's third persona was Dude Love, a hippie character inspired by the tapes he used to make as a backyard wrestler before he made it big in WCW. Dude Love was much more easygoing than his two other personas and dragged Foley's real-world history into WWE storylines, a popular tactic in the Attitude Era.

During the Royal Rumble match in 1998, Mick Foley entered the match three times portraying each of his three personas. Perhaps The Undertaker intends to do the same in the mysterious Boneyard? There is no shortage of different Undertaker incarnations he could resurrect, from the Deadman to the American Badass, the Last Outlaw character he adopted in the early 2000s, or even his brief Phantom of the Opera character. With the Boneyard match pre-taped thanks to the surreal, empty arena state of WWE at present, all manner of editing or special effects could be used for Undertaker to pull this off.

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One other potential inspiration for The Undertaker's Unholy Trinity concept could stem not from wrestling, but from the Marvel universe. In The Incredible Hulk #337, comic book fans were introduced to a Hulk incarnation known as Merged Hulk. Merged Hulk was an amalgamation of Grey Hulk (the original Hulk before green was chosen as his primary color, who was later revealed to be a separate entity), Green Hulk (the most well-known Hulk form, renowned for his rage) and Bruce Banner all merged into one single being. Merged Hulk is also the main inspiration behind The Hulk's portrayal in the Marvel Cinematic Universe.

With many feeling like Taker's better days are behind him, the Unholy Trinity just may turn out to be The Undertaker's final form, a combination of every Deadman character that has stalked the graveyard throughout his career. If true, it could turn out to be a fitting end to Taker's career -- just as long as he leaves the purple-tie clad version of the Undertaker who entered the ring to Limp Bizkit at WrestleMania XIX to "Rest In Peace."

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