Explosive Shurikens

Explosive Shurikens are the specialty and signature weapon of Naien, later inherited by Hotaru Yanma; who uses slightly different version of this weapon.

These are throwing weapon used by Naien as a lethal/non-lethal ranged attack depending upon the type and situation. These are made of a very soft and light weight alloy which consists of two layers of ingredients (Naien's version) on applying a certain pressure to these devices they would explode within 4 seconds after they are thrown, there are two sets of explosions that take place, first one is a chemical mixture of 48 KNO3 + 5 C12H22O11 → 24 K2CO3 + 36 CO2 + 55 H2O + 24 N2, hence dense smoke, while the second explosion is of Nitrous oxide, commonly known as laughing gas. Since tt has no color, smell, and doesn’t irritate, the second explosion remains concealed.

Hotaru's version
Hotaru uses hawk shaped shurikens which has similar effects but it contains Bromine monochloride instead of Nitrous oxide and these shurikens are evidently more lethal and sharper.