Things that seems to be wrong

Ok:

-Wasn't Lumiya weaker then the cyborg vader? Then how the hell he gave that much trouble to Luke? Hmm...

One reason was due to her lightwip,then Luke partially blamed himself for her becoming a cyborg, and she played mind games that made it hard for Luke to go all out,until Mara died and then Luke annihilated her.

She wasn't giving him trouble, he held back. If you read Sacrifice where Luke was determined to kill her, she didn't stand a chance. She commited "suicide-by-Skywalker".

'Nuff said.