While leading the 39th Army Group of the National Revolutionary Army, he planned to defect to the Japanese, but before he could do so he was kidnapped and buried alive by his sworn brother and subordinate Gao Shuxun, who later gained command of Shi's unit.
Being buried alive, piranhas, quicksand, "stop drop and roll", the Bermuda Triangle - all things I feared growing up and thought would be more relevant.
Before the end of WWII, Japan was not well regarded in Asia, they were warlords and colonists pillaging the mainland whenever they could for centuries.
According to this Lemmy thread, he actually got caught and buried alive by his sworn brother at the end, because 6 betrayals is one thing but 7 is another, I guess.
TBF, that was a fighting between warlords period. The people he betrayed were no more loyal than him.
Feng Yuxiang betrayed Wu Peifu, following Zhang Xueliang's advice. Zhang later surrendered to Chiang Kai-Shek himself. So it was basically everyone trying to grab any opportunity.