The Mark of Tarakudo is a magical symbol bearing the face of Tarakudo, King of the Shadowkhan and Lord of All Oni. The mark will appear if one were to attempt to summon the Shadowkhan to do their bidding. Any human who tattoos this Mark onto their body will gain the ability to summon and control Ninja Khan without wearing an Oni Mask or using a dark spell. However, doing so will gradually turn the person into an evil demon with blue skin, red eyes and fanged teeth, making them resemble a Shadowkhan themselves (while also allowing evil within the tattoo to consume their very being).