I saw this a few years ago and still love it so much. Mostly for the music, especially the female vocals which send a shiver down my spine, but also for the execution of this animation, using Slavic mythology I believe. The animation was created for the Russian band Theodor Bastard.
A tiny google search later and I found this site with brief descriptions of aspects of Slavic mythology. From this I chose a few pieces of information which I think could have influenced this animation. It's all guess-work and my own interpretation as I couldn't find any information about the animation, nor the Russian animator. But here goes:
Perun is the god of thunder and lightning, very similar to Thor. His name comes from the root "to strike." He carries an ax or mace, his sacred animal is the bull, his sacred tree is the oak. He has dark hair with a long, golden beard, and is sometimes portrayed with three heads with fiery-red faces surrounded by flames. A perpetual fire was maintained in his honor; if it went out, it was rekindled by the use of a stone. Worshippers laid arms at his idol's feet, and stuck arrows around oak trees in his honor. His idol was thrown into the Volkhv River when Christianity came to Russia. A six-petalled rose within a circle was carved on roofs to protect houses from thunder and lightning, and the symbol may have been associated with Perun. Perun became Ilya of Murom in epic tales, and St. Elijah in the church, because the saint's chariot rolled like thunder and his arrow was lightning. Perun was also associated with St. George, since he slays a dragon (Volos). St. George is the patron of wild and domestic animals.
Navky, spirits of children who died unbaptized or who drowned.
Rusalka, the spirit of a child who died unbaptized or of a virgin who drowned. Rusalki live in lakes and have long, wavy green hair. Some have fish tails like mermaids, and some can turn into fish. They manifest either as beautiful girls, dressed in robes of mist, who sing sweet songs to bewitch passersby, or as ugly and wicked women who attack humans, especially men. During Rusalki week, around Midsummer, they emerge from the water and climb into weeping willow and birch trees until night, when they dance in rings in the moonlight. Any person who dances with them must do so until he dies. After that week, the grass grows thicker wherever they walk. In the 19th century, the Rusalki were connected with the cult of the dead.
Spor, the embodiment of fertility, who watches over the corn and cattle.
Vodyanoy, a malevolent water spirit who likes to drown humans. He will attack anyone who swims after sunset, or on a holy day. He can appear in different shapes to trick his victims. The Vodyanoy lives alone in his body of water, and he especially likes rivers with strong currents and swamps.
Vodni Panny, sad and pale water nymphs, who dress in green, and live in underwater crystal palaces.
Turisi - January 6
This is the day of the bull, Jar-tur, a symbol of life and fertility. People celebrate by wearing masks, parading and imitating the bull. They play games called "Turisi". This also ends the period thought of as the New Year holiday.
Rusalka's Week - June 19-24
On the Thursday preceding Whitsunday, women go into the woods, singing, and pick flowers to bind into wreaths. The men cut down a birch tree, and the girls decorate it. A ritual meal of flour, milk, eggs and plenty of beer and wine is eaten. After the meal, the tree is carried into the village and put into a special house to be left alone until Sunday. The tree becomes the focus of girls' songs and dances, then it is thrown into the river at the end of the week. On Whitsun Monday, a small shed covered with garlands is erected in an oak grove. A straw or wooden doll called Rusalka is decorated and put inside. People come bearing food and offerings. At the end, the doll is destroyed by burning or drowning. Sometimes a girl or horse replaces the doll and undergoes a mock funeral. This celebration is connected with the Rosalia, the Roman festival of roses. See "Women's Trance Ritual."
This also made for interesting reading.
And here is another Theodor Bastard video which I rather liked...
Theodor Bastard - Mir Album version from Nick Nickandrov on Vimeo.