Unlike ancient Greek or Egyptian, Hindu and Chinese mythology, there are no written records of Slavic mythology before the arrival of Saints Cyril and Methodius to Slavic lands in 862.
Archaeological evidence of old Slavic cult images and shrines have been found, but little can be extrapolated from them other than confirming existing historical records.
But, fragments of old religion can be found surviving still in folk customs, stories and songs.
Lots of christian saints bare the traits of old Slavic gods due to rapid conversion to Christianity most famous being St. Ilija / Perun combo.
As Christianity was introduced as a religion of the elite, for the rural majority of the medieval Slavs, old myths remained strong.
Christian priests in Slavic countries, fought against dvoeverie for centuries, because to Slavic peasant, Christianity was jut an addition to an old Slavic religion. So it all became the melting pot of Slavic and Roman paganism, Christianity and when tribes began coming from the North, even the Nordic mythology!
Magic rituals are practiced to this day in some rural parts of Bulgaria, Croatia, Serbia, Bosnia and in Russia there is a whole part of Siberia where Christianity never came and old religion is very much alive.
Collecting myths, legends and magic of the old Slavic religion is fascinating to me! Old gods, old magic...
Much more interesting to me than Nors mythology that is so popular around the world.
What do you think, which religious customs Christians in Slavic countries follow today are actually Slavic pagan magic rituals?

I have heard something from my friends from Balkans, and I would like to know if that thing is true. I first heard about this magic ritual few years ago, when my friend from Croatia jokingly sad something about menstrual blood in coffee as a love spell. Than i heard it a couple of more times from different Balkan people, but always as a joke. Is it a real thing or some pun I don't understand?

As a person from Balkan region I must say I am not sure about that coffee and blood thing either Maybe it is an urban myth maybe it is true, one can never know with south Serbian people

As for Slavic custom and modern religion... welll... So many things are there, mixed with other religions Christianity brought fragments off... But at the end, painting of Easter eggs red (and Easter eggs in general) and burning of oak tree are I guess most famous of all Pagan to Christianity conversions of custom

No matter what mythology were speaking of here, there are less and less rituals performing.
I would burst from happiness everytime I see some nature movement (not hippy ) or crowd.

There was rather good article few years ago regarding pagan tribes of the old continent.
As you see here, even Nordic tribes were paying respect to other tribes in old Europe.
Doesnt have to be pre-christian era.

Balkan region was obviously pranked as "Fallen heroes" . what could this means MumboJumbo?

This is why I can't take any religion seriously... Christianity professes to preach the one and only truth of god, the world and our place in it, while at the same time assimilating traditions, customs and aspects of other pagan religions that outright contradict the "truth" of Christianity. And the major religions aren't the only ones that do that, the same can be said about Slavic mythology, Norse mythology or any kind of religion, ancient or new. There is no religion (or mythology or set of beliefs) on this planet that hasn't been warped or influenced by some other, past or present, religion. A religion that has remained pure and untainted by other beliefs since the moment of it's inception to this day would have to be some really primal animistic shit, and I honestly doubt anything like that has survived until now.
Don't get me wrong, I love Slavic mythology, Norse mythology, Greek mythology, shit, any kind of mythology! It appeals to the fantasy lover in me and is such fertile ground for amazing stories and adventures, whether they are original legends from the mythology in question or newly made up stuff derived from and inspired by mythology. But having said that I would never consider them a viable belief system, no more than I would consider Christianity or Islam. People who spit on the modern major religions and call them fake or fabricated while prescribing to old, "true", pagan religions are full of shit. There are no original religions (unless you go back in time and ask some caveman what he believes in) and there are no true religions... that is why I call myself an agnostic, If there is some all powerful creator out there (and I can't and wont discount that) he sure as shit isn't Buddha or Jesus or Allah or Perun or Odin or whoever the fuck.

I'm sorry about this word wall rant, I guess even if it mentions Slavic mythology it doesn't have much to do with the topic itself. I didn't get to vent in the "Do you believe" section so when I got triggered by talk of fusing Christianity and paganism I couldn't help myself