Urn of Wei Cheing

The Urn of Wei Cheing is a one-of-a-kind magical artifact. The episode The Powers Unleashed (start of season 3) saw Daolon Wong attempt to infiltrate Section 13 and gather the twelve talismans for himself. However, he was caught by the Chans, who also caught the Enforcers attempting to steal the talismans. Daolon Wong was the greater threat, but Uncle and Tohru were prepared with this Urn, using its magic to capture and contain his three Dark Chi Warriors within it.

This was a major surprise for Daolon Wong, and when the talismans were destroyed by a laser blast in the resulting scuffle, there was nothing left for him to do but retreat. However, he knew the talismans' magic still existed, so he transformed the Enforcers into new Dark Chi Warriors. There was no more room in the Urn for these warriors, and the Chans had no backup method for another capture.

The Urn was never seen again, but neither were the original Dark Chi Warriors, so it is a good guess that they are still trapped.