u/Fun-Abbreviations-66

So, I decided to try Legends. I managed to get one Survival match (my first legends ever), and I tuned out to be second with 37 kills.

Now, I am trying to do any missions, but I am the default samurai, and have only the Odachi and double blade as a weapon.

I have googled Legends, but the explanations are a tad fuzzy. Do I have to complete the stories to unlock all the weapons? Do I have to do them alone? Do I have to do all story missions?