There was an image of mahAkAla which was made for Qubilai Khan & had great significance among the Mongols. Its possession designated the Mongol Khan as the supreme upholder of the dharma-chakra. As the Mongol empire fragmented, it passed from one minor Khan to another. The final descendant of Chingiz Khan to possess the idol was Ligdan Khan of the Chakhar branch of Qublaiids.
He wanted the remaining Mongols to submit to him - but interested in keeping their uluses they formed an alliance with their former enemies the Jurchen. Chief among latter were the Khalkha Chingizids & Khorchin Khasarids. The princess of the Khorchins was the wife of Nurhachi of the Jurchen, soon to be Manchu. This entente defeated Ligdan Khan & he fled to Kokonor where he died. Some Mongols presented the idol & the Chingizid seal to Nurhachi’s half Mongol son Khung Taiji. Now in possession of that sovereignty conferring idol he was able to declare himself lord of all the Jurchen & Mongols. It is not known if the Maoists destroyed that idol or it has merely been lost somewhere in Manchuria.
But the Oirat Mongols did not accept this arrangement, declared themselves as the true dharmapAla & conquered much of the Chingizid Mongol territories & also Tibet, where the puppet Dalai Lama installed by them confirmed this position of theirs. This was followed by their pact with the Chingizids who did not join the Manchus (known as the “great code” which some have compared to the Mongol version of the Westphalian pact). This of course led to conflict with the Manchus who insisted that the mandate of heaven had passed from Chingiz Khan’s line to them. It finally ended when in 1757 CE the Manchus & their allies erased the Dzungarian lineage of Oirats by committing a genocide of over a million people.