To clarify what Danzo said, you can revive a total of 3 times, it can be the same ninja 3 times or 3 different ninjas, but a total of 3 revives per masuri

Also, an additional possibility, since this was not explicitly excluded in the OP, if all your ninjas die, masuri ends, regardless of whether you have used revive or not. So if you are on your last team and intend to revive anything in the event that you lose, you should revive ONE of the ninjas before going into battle with your last team.