Yugi saw his face and said “Yami…knowing Serena, what you  did for her couldn’t have been the cause. From how Bane sounds…he wouldn’t have let that happen.”

She said “it’s worth looking into. To see if your magic could be something Apep doesn’t know so in turn could stop him. If there was a way to test it…” 

Serena said “there is. He next battle we have with him. We sick the knights on his magic. That knight from last night stopped me cold. That’s got to mean something”