How to get amertetsu on ninja saga on fb?

To obtain Amertetsu in Ninja Saga on Facebook, you typically need to complete specific missions or events that may offer this character as a reward. Keep an eye on in-game announcements or events that might provide opportunities to unlock Amertetsu. Additionally, participating in special challenges or purchasing from the in-game shop can also yield chances to acquire him. Always check the game's community forums for tips and updates on availability.