The Alkonost and the Sirin are two sides of the same coin. Both are beautiful women with the bodies of birds and both have magical voices of unimaginable beauty. The Alkonost guards good fortune by day and the Sirin by night. You cannot separate the two, because one is simply the alter ego of the other
ALKONOST
Her voice is supposed to be so beautiful that she can make you forget anything that hurts you. She is said to sing about the beauties of paradise for the saints so that they don’t give in to despair and temptation. Other stories claim that wars have actually ended due to her voice
SIRIN
Birds with black feathers are often attributed as being conduits between this world and the other side, bringing messages from the dead. It is no surprise then that the Sirin has dark plumage like a raven or a crow. Given that she is just the Alkonist’s alter ego, it could be argued that it is her divine duty to punish the wicked and usher the dead to their afterlife. She is, after all, still a guardian of good fortune