Grenade--Explodes on impact. It's tough to score damage unless you hit an enemy directly. If you drop one on the ground, attempt to lure the enemy nearby. Grenades are also useful as added damage potential against bosses.
Poison Rice--Causes temporary paralysis when eaten. Drop the piece of rice within view of or within the path of an enemy. He'll walk over to it, bend over, pick it up, and then eat it. If the guard eats the poison rice, he'll be temporarily disabled, providing a perfect opportunity for you to execute a stealth kill. But it's better to approach and attack the guard when he's walking to the rice or bending over to pick up the rice. If the guard fails to eat the rice, you can pick it up for another use. Poison rice is particularly useful around corners or for guards patrolling on a floor below you. You can't use poison rice on the undead or the mechanical enemies that populate the castle.
Mine--Explodes when stepped on. Drop a mine in a guard's path and watch the destruction, though it may take two to eliminate a foe.
Sticky Bomb--Detonate with the R3 button. Toss this shuriken-like weapon, and it will embed itself in an enemy or boss. When desired, push down the right analog stick to detonate the bomb. Sticky bombs are most useful against bosses, since you should be attempting to avoid combat most of the time. Throw one on a boss, and when he's low on health, detonate the sticky bomb to finish the job. They are especially effective against Onikage's second incarnation--prevent him from using that healing potion!
Tiger Trap--Clenches the feet of fools. You plant it like a mine, but when an enemy steps on the tiger trap, it doesn't explode. Instead, the enemy becomes stuck in the trap. Upon trapping the enemy, execute him with a stealth kill or just ignore him.
Tetsubishi--Hook and pull guards closer to you. You most likely won't use this very often. Tesshu has a similar item (one that's unlocked by achieving grand master status) that actually combines the pull with a stealth kill.
Colored Rice--Use this rice to mark a trail on your map. Drop rice to denote where you've been on a level. Check the map so you won't backtrack accidentally to that area. You could also use colored rice at an intersection so you can explore one route then return back to the colored area on the map to explore the alternative.
Strength Potion--Increases attack strength for a limited time. This potion is useful against bosses or if you're up against multiple guards. It's a one-time-use potion; once you drink it, the potion is gone.
