does anyone know if there's any canon, that covers possible cults or other kind of devoted who worship the Wardstones around the Worldwound ?
Possibly with the belief that prayers will reinforce it or that they'd bestow them power to fight the demons ?
The stones are still very recent things and the area is overflowing with very active major religions, including a bunch of people really into witch-hunts.
Hard to develop a new faith around something entirely new in those conditions - especially around what are still at their core tools of the Crusades and the Iomedaean cult. With links to Sarkoris Shamanism.
Extremely powerful tools, sure, but still.
That said, prayer and ritual is indeed a part of what powers them. They're not the object of the cult, but they're certainly part of it.
Of course, people get weird, doubly so in that kind of environpent, so who knows ?
Stone worshipping sects might exist, although they wouldn't have any effect on the wardstones themselves, nor are they likely to ever approach them.
And they'd effectively be worshipping artifacts their parents or grandparents witnessed the creation of.