Board Thread:General Discussion/@comment-4519633-20141022032431/@comment-3398493-20161206000828

But Merlin's power was converted to Dark One power... And Rumple has the power of every Dark One including Nimue who was Merlin's equal...

Tcweh wrote: I've figured out a possible theory for Zelena vs EQ and this would be acceptable for the writers to incorporate in the show (but they never will lol)

Regina has simply trained and gotten stronger since S3. And by extension, so did the EQ. Zelena on the other hand has mainly been paying attention to her baby. Zelena didn't bother to attack the Queen because she knows that she can not kill her. And she has grown soft and has an inner conflict... Zelena is stronger than her sister EQ or not.