((YOU MUST HAVE SAMURAI CLASS))
To become a Samurai, you will first have to talk to one of the leaders or "Devils". He will then put you through a trace that will whip away all your knowledge of jutsu, but allow you to tap into your sword. IN SHORT you have to get rid of all your jutsu, all things that make you a ninja.
In return you will get 2 advanced elements. If you have a doujutsu, you will keep the doujutsu and gain an advanced element.
Next, you get unlimited Abilities, HOWEVER all abilities have to be related to your sword.
TO CLEAR THE AIR
You cannot have two doujutsu
You cannot have uchiha and senju
So no sharingan + wood and try and get yin-yang