#5 and #4 Rusev and Lana

Unlike the Kanellis', Rusev and Lana actually have had real momentum in WWE on a few occasions.
They hit the ground running on the main roster as ruthless 'Anti-American' heels complete with a run with the US Title and a feud with John Cena.
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But once that lust wore off, they were shuffled down the card a little after a debacle of a feud involving Dolph Ziggler and Summer Rae.
Although announcing their engagement on social media while they were embroiled in a feud that saw them on separate sides wasn't timed the best, they rebounded from that with the hilarious 'Rusev Day' gimmick, which actually seemed to have happened by mistake.
During a backstage bit with the New Day, Rusev said 'No once cares about New Day, only Rusev Day.'
And from that, one of the most popular acts of 2018 was born. Mr. McMahon didn't seem to run with it as he should have, only giving Rusev a shot at the WWE Championship rather than giving him a meaningful run with any major title.
He did win the US Title earlier this year but lost it almost as quickly as he formed a partnership with the man he was feuding over the title with.
Now, he and Lana just seem like supporting pieces or parts of an extra team whenever a match or storyline deems it necessary, like the gauntlet match on last week's SmackDown.
Lana is also very outspoken on social media and even Rusev said it was frustrating to come up with ideas and constant pitches only for them to fall on deaf ears. They'll be a huge gain for whichever promotion signs them once they leave the WWE.