Speedy Ninja – What does it mean by “revive with two of your unlocked ninjas”?

For example, if you are in the Title of Generalist, then you can revive with two of your ninjas. This means that you need to have at least three unlocked ninjas, one to run during the first life, the other two to continue as self-revive after the first life. If you have only two unlocked ninjas, you could only do one self-revive.