The Mark of Tarakudo is a magical symbol bearing the face of Tarakudo, King of the Shadowkhan and Lord of All Oni, more well known as the symbol of the Shadowkhan. 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 the Shadowkhan 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).
The tattooed Mark cannot be removed unless a magical potion is used or by a magic spell in sealing Tarakudo and his shadow magic away. Tarakudo himself has a magical link to such symbols — either by a tattoo, through the dark spell or directly through the Oni Mask in summoning Shadowkhan. He even possess awareness of those who used such magical links.
- Queen of the Shadowkhan (Season 2)
- Sheep In, Sheep Out (Season 3)
- The Masks of the Shadowkhan (Season 4)
- The Amazing T-Troop (Season 4)
- Ninja Twilight (Season 4)