When you attack with a shuriken, there is a chance of summoning the shadow warrior, who will aid you in battle. Shinobi will accumulate chakra over time. Accumulate enough chakra, and you can cast an arcane spell. When you cast a spell, the Shadow Warrior will also use his skills to assist.
When using the arcane spells Shadow Assault, Great Fireball, and Razor Wind, different amount of chakra will be consumed. Chakras can be stored up to 5 and accumulate over time; 3 seconds when using shuriken as main weapon and 9 seconds when using shuriken as sub weapon.
When skills are cast, there is a chance of summoning a Shadow Warrior. The player can choose between Slasher, Dancer or none of them. The player can't switch options while in combat.