Heart of Tengu

"The Heart Of Tengu" is a mystical artifact that allows whoever is in possession of it to control the five elemental mystics who served the Demon Shredder, and also protected whoever carries it from attack. It is assumed that this artifact was created by the "Ninja Tribunal" before or after they had defeated the Demon Shredder, as their symbol can be seen on the artifact in the episode "Good Genes, Part 2", as a way to keep these powerful Mystics in check as their master was.

At some unknown time the Utrom Shredder came into possession of this artifact and used it to control the sealed away Demon Shredders heralds, and even though it appeared that the mystics were loyal to Ch'rell when they attacked the turtles in the episode "Return To New York, Part 2", it was later revealed in the episode "Fathers And Sons" that they were discusted at serving him and hatched a plot to resurrect there master by using an invisible bone demon to gather the helmet, gauntlet and body from the "Ninja Tribunal", but it was defeated by Master Splinter and the Ancient One. It is unknown if the Mystics made any other attempts after this to free themselves but it did not take long after their mistreatment at the hands of Karai that they became more determined to free themselves and after tricking the E.P.F. into stealing the artifact and destroying it, set out to revive the Demon Shredder. It was also revealed that the Mystics at some point in time sent out there demon servants to steal the gauntlet and helmet from the Tribunal and when they arrived in Japan they found their servants defeated by the new acolytes of the "Ninja Tribunal", who were in fact the turtles and 4 other brave warriors chosen by the tribunal. After a massive attack on the Lap Of The Gods, the Mystics succeeded in recovering the Demon Shredder's helmet, gauntlet and body and eventually revived the true Shredder.