Rawles duke then king Uther can have a good night with Ylgerna. We may think this is crazy Merlin has done something bad. But it was actually a good thing, because prince Arthur was born after that night. When Arthur was 15, Merlin helped him to get a sword and the sword helped Arthur won a war. Merlin also used magic to help him to win a war he used to be a teacher to Arthur. He taught Arthur a lot and helped him a lot. But he is not always right he is the guy who led to the kingdom to death.