Nags Explained:
More commonly known as witches or hags, their full name is Naginas with the 'g' pronounced like a 'j', they aren't simply magic users or fairies as folklore would have you believe and are in fact powerful gods incarnate. Kadru and Vinata were both the wives of the powerful sage Kashyapa. Kadru asked for many children and Vinata asked for powerful children. Kadru gave birth to snakes and Vinata to a god and powerful beast called Garuda.
Kadru made a bet with her sister Vinata with the stakes being that the loser was enslaved by the winner. Kadru asked for the help of her children in fixing the bet but they refused so she sentenced them to death at the hands of king of men, Janamejaya. The king of the snakes, Vasuki, who was the favorite of the god Shiva, enlisted the help of the great sage Jaratkaru, who married Vasuki's human sister Manasa, who was a goddess from being the child of the god Shiva. Jaratkaru and Manasa went on to have a human child named Astika. Janamejaya was only meant to kill some of the snakes but enjoyed watching them burn so much that ordered them all to be killed. Astika being very clever, praised Janamejaya on his fantastic show of power, and being flattered by Astika's praises, Janamejaya said that Astika could have anything he wanted, to which Astika asked for the ceremony to be drawn to a halt. Annoyed but not wanting to look like a liar in front of his people, Janamejaya ordered his men to stop the sacrifice.
After Vasuki helped create the elixer of life, which later the gods acquired, Garuda, being annoyed that his mother Vinata was the slave of Kadru, asked the Nags how to break the agreement Kadru had made. The snakes asked Garuda to steal the elixer of life for them which Garuda did after fighting his way through various traps protecting the elixer. However on his return to the snakes he came across the god Indra who he promised the elixer to so she could return it to the gods in exchange for granting Garuda the ablity to eat the Nags. When Garuda returned he tossed the bottle onto the grass before the Nags. Seeing his promise fullfilled they freed Vinata, but when he distracted the Nags by requesting that they prepare for a religious celebration, Indra swooped in and took the elixer. Panic stricken, the Nags licked at the grass to get some of the elixer, splitting their tongues but also becoming demigods in the process. Since that day Garuda has devoured the Nags at every opportunity though after promising to be Vishnu's mount in exchange for immortality has had little free time to do so.
Nags are beings that are half snake and half human, and although they normally take the form of being which has the upper half of a human and the lower half of a snake, they can turn any part of their human body into snakes including but not limited to their limbs, fingers and toes and facial features. They are blessed with immortality as in eternal life and also only being able to be killed via magical means. They are powerful mystics and are protected by gods as well as powerful magic users themselves. Capable of healing curses, illnesses and other ailments they can be a powerful force for good but equally they are capable of giving curses, illnesses and ailments to others. They are immune to poisons and toxins but also capable of delivering a variety of poisons and toxins with various types of effects. Although they have the body of a beautiful young adult, often their shedable skin can make them appear wrinkled and old. Their spells can cover large areas, large numbers of individuals of a particular group or large numbers of items, though these spells act gradually getting stronger over time. For more powerful or immediate effect their spells can be cast on individuals, small areas and individual items. Although not as dramatic as a storm god's magic, their magic can cause much greater effect over a longer period of time. Often very slow and deliberate in their actions, they are not equipped for direct combat and tend to avoid it, though capable of being very quiet and using camouflage and shadows to their advantage, they are known for being exceptionally talented at stealth and often attack from behind or from a distance using ranged attacks, often using paralysis and blindness spells to get close where they can wrap up their victims in an inescapable bind. Most rely on smarts or persuasion to succeed and they can be exceptionally patient, often having long-term well-thought-out plans for success.
Master biologists they are known for brewing potions using ingredients they find around rural environments, in particular plant and animal extracts, though these are also helped with aid of magic as well and often human items work much better than animals or plants. Often possessing the ability to predict the future, they often reveal it to inquizative individuals through metaphors so as not to upset the course of events. Other powers vary with some adapted for water, having fins and capable of breathing underwater, some are adapted to the cold generating fire inside their chests which they can project from their mouths and some are adapted for darkness being black instead of green and having night vision.
Though often wrongfully believed to be later Christian influence on the Nag legends, the Nags are known for consuming souls or living prey and often that of humans in particular, even among Nags who are considered to be aligned on the side of good. Though they can eat dead animals, they get magical power from souls and live prey which contain souls and also seem to really enjoy it like a tasty dessert, often giggling with laughter and rolling around on the ground in excitement with the mere suggestion of it in an uncharacteristicly child-like fashion, as if it's an addiction. Human souls with or without their bodies are prized higher than others amongst Nags and Nags often have methods for trapping souls and carrying them around with the Nags in small trinkets so that they can use them later. They can also use this technology for good however as they can manipulate spirits into protecting precious items, places or individuals or using their energy to enchant lucky charms that protect the wearer or the location they are placed in. They also have power over wandering spirits and the undead, as well as being able to bring the dead back to life, turn the living into the undead and turn undead people back into the living.
Though particularly helpful or damaging to mankind in particular their slow nature means they are unfortunately often preyed upon by other mythological creatures, in particular bird-like creatures such as Harpies, Griffons and Chimera. In modern folklore they are believed to live amongst human traveler colonies or Neo-Pagan communities disguised as humans, often protected by these people in exchange for the aid of the Nags magic powers, and their modern motives are not that of trying to eat human souls but just to enjoy the pleasures of life without having to worry about persecution from witch hunters, though there are still rogue killer Nags.