Sadly , we haven't got the 7 swordsmen of the mist for a really decent team , but as alternatively , you may try this:
Note: As you haven't mentioned what ninjas you got , i'm including Chojuri and Darui.
X - Lightning Main - Chojuro
X - X - Darui
X - X - Danzo
Talents : 3-2-1-3-3 with summon: Serpent
The team really got TONS of damage , you can see the demonstration here , but with Ningendo instead of Danzo(skip to 10:33): https://www.youtube.com/watch?v=ZttVxYloxrE&t=963s
Good luck!