Ki (気 Ki?) is spiritual life energy that ninja and other beings use to perform various supernatural effects, including the casting of Ninpo or performing more physical techniques.
Classic series[]
Ninja Gaiden[]
In the NES Ninja Gaiden "ki" appeared as Spiritual Strength and was represented with 忍 (Shinobu) and a number. Each technique or ninpo equipped costs a set amount of ki. To recover his ki, Ryu Hayabusa must collect spheres marked with 忍, which come in two varieties: blue which recovers 5 and red which recovers 10.
Item | 忍 Cost |
Throwing Star | 3 |
The Art of the Fire Wheel | 5 |
Windmill Throwing Star | 5 |
Jump & Slash Technique | 5 |
Ninja Gaiden II: The Dark Sword of Chaos[]
Ninja Gaiden III: The Ancient Ship of Doom[]
Ninja Gaiden Shadow[]
Ninja Gaiden X[]
Modern series[]
Ninja Gaiden[]
Ninja Gaiden: Dragon Sword[]
Ninja Gaiden II[]
Ninja Gaiden 3[]
Standalone games[]
Game Gear Ninja Gaiden[]
Master System Ninja Gaiden[]
Ninja Gaiden Clans[]
Trivia[]
- Although known to be a ninja attribute the protagonist of Yaiba: Ninja Gaiden Z, Yaiba Kamikaze, was incapable of applying his ki.