|Jewel of the Demon Seal|
|Debut||Ninja Gaiden (Xbox)|
The Jewel of the Demon Seal are special jewels can be found in Ninja Gaiden (Xbox) and Ninja Gaiden II. When used they will upgrade one ninpo technique to the next level. One jewel grants one level. A ninpo technique can be upgraded up to three times. After which no more jewels can be placed on the technique.
A jewel that shines dark purple. It can be used to increase the potency of certain Ninpo techniques.
Ninja Gaiden IIEdit
Permanently increases the level of a Ninpo spell.
A violet jewel that can strengthen the level of any Ninpo technique. The jewel resonates with the human consciousness, inspiring a greater degree of control over one's Ki. The jewel is known to consist of Dragon secreations (Dragon drops) that have stabilized in the crystal matrix of chalcedony as a piezoelectric substance. The Jewel of the Demon Seal has long been sought after by those who wish to reach a higher spiritual plane, such as fortunetellers and practitioners of meditation.
- Some players save Jewel of the Demon Seals until they pick up a particular ninpo they like and max out it's levels.