The Indian cult mentioned is actually worship of a fallen angel, quite demonic, and many in that cult were very possessed. It still isn’t dead.
It should also be noted a great peculiarity, that the Thuggee among their numbers didn’t just have Hindus, but also Muslims and Sikhs, yet differed from ordinary dacoits(*) (highwaymen) with their elaborate subterfuges and schemes, as well as a total lack of discretion in choosing their victims. Any caste, and even British.
Today, the Kali cult has been absorbed back into a branch of Shiva worship (Kali was a version, an avatar, of Shiva, according to their myth), and this branch practices “pseudo-murder” with young children, such as dropping them from a high temple yet catching them; or digging a hole, putting the child in there with a blanket over them, then shoveling dirt on the blanket, to ritually “bury” them, before pulling up the blanket and dirt and removing them from the hole.
But every now and then, some Shiva priest is accused of being unsatisfied with pseudo-murder and butchering a few children for real.
The Thuggee were so discreet in fact, that for a long time they operated without British knowledge. Only when a group of them were arrested and set to be hung did the light finally dawn. Up on the gallows waiting to be hung, the group cried out to their goddess, then jumped off to die instantly. This got the attention of the British.
So the British arranged for a top notch criminologist from England to take over the national police, who used modern forensics to dismantle and finally destroy the cult, to the great relief of all. Not too many policemen get entire regiments of soldier at their command.