Oberyn has some major, major beef with The Mountain for what the giant did to his family, though on a direct, personal level, The Mountain psychologically broke his brother Sandor and scarred him for life. Sandor would be a strong contender to bring him down. He's one of the only men who could almost match him for strength, and it's a fight fans crave to see. Method Of Elimination: Once Gregor was out of the picture, Sandor would have nothing left to fight for. His mission would be complete and while he wouldn't roll over, his thirst for blood wouldn't be the same. Ultimately Sandor would probably be brought down with his greatest enemy. Fire. It tortures him, and it could easily kill him.
7. Daario 'Not Ed Skrein' Naharis
Daario Naharis must have gone under the knife while under Daenerys' command due to one minute looking like Ed Skrein, and the next he'd remarkably resemble Michiel Huisman. He's a natural-born fighter after being raised up from poverty through the fighting pits to what he is today, a leader among Daenerys' camp. Method Of Elimination: Like Oberyn, Daario fancies himself as the rockstar, the smooth-talker, the playboy. That could work to his disadvantage, though the bigger concern for his survival wouldn't be anything to do with Daario, it'd be due to the man who would love to kill him for the undisputed Lord of the Friendzone title...