#6 Becky Lynch
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If Io Shirai were to end up on the blue brand, a feud with Becky Lynch would be one of the first things that come to mind. Though Becky Lynch's style isn't as death-defying as Sasha Banks', she has an explosive, mostly ground-based offense that would contrast very well with Io Shirai's aerial maneuvers.
The match could be built around whether Lynch could keep Shirai grounded for long enough to lock in the Dis-Arm-Her. This would be a difficult thing to do, because Shirai is so quick on her feet and nimble, while also boasting a strong grappling arsenal herself.
Lynch playing the consummate fiery babyface while Shirai plays a more vicious character would also do much to get the crowd invested in the outcome.