Strigoi, like the dhampirs, are subspecies to the Moroi vampires. They’re everything you’d expect an undead vampire to be: strong, fast, and extremely bloodthirsty. Strigoi, unlike Moroi, are made and not born. There are several ways to become Strigoi, none of which are considered pleasant.
BECOMING A STRIGOI
By Force - Whether you are human, dhampir, or moroi, you are always at risk of turning Strigoi by force if you’re unlucky enough to encounter one. They will drain you of blood to the point of death, and force-feed you their blood to complete the transition.
By Will - You also have a choice to become Strigoi on your own terms, though it is considered a taboo act. Those who become Strigoi willingly are essentially disgraced, as demonstrated by the consequences the members of the Ozera family faced when Lucas and Moira willingly turned.
For Moroi - Moroi can become Strigoi either by allowing a Strigoi to turn them, or they can become Strigoi by purposely killing while feeding. This is considered an unforgivable act of nature, and strips the Moroi of not only their elemental magic, but their life and curses them to a life of darkness away from the sun.
Some Spirit users may choose to become Strigoi as a means to escape the pain and mental torment that comes with being a Spirit user. Turning Strigoi strips you of your elemental abilities, which negates the negative effects of Spirit. If you are restored, you gain your elemental skills back. Sonya Karp, a former teacher at St. Vlad’s Academy, was a Spirit user and did this to get rid of her Spirit magic. She was later restored to a Moroi by Robert Doru, Victor Dashkov’s half-brother.
For Dhampirs & Humans - Though the most common method of turning Strigoi is by force, dhampirs and humans may choose to be Awakened willingly. Humans and dhampirs that want to be Strigoi often make extremely risky deals with the Strigoi in exchange for immortality. Dhampirs that choose to be the very thing they’re supposed to fight and kill are most likely disgraced even more than Moroi who willingly turn.
KILLING A STRIGOI
There are three ways to kill a Strigoi: Staking, burning, and decapitation.
Staking - Dhampir guardians use a special silver stake that has been infused with fire, air, earth, and water. Since Strigoi are undead and magic is “alive”, the magic hurts them. If a guardian can get a clear aim, they plunge their stake into the Strigoi’s heart and it kills them instantly. It is this magic that fuels the protective wards around places such as St. Vladimir’s Academy in Montana and the Moroi Royal Court in Pennsylvania.
Burning - One of the best and most effective ways to kill a Strigoi is by burning them. Moroi like Christian that have specialized in fire can prove to be extremely useful, especially if their magic is powerful enough. Another good option is using a flamethrower. Strigoi cannot withstand the sun’s rays, either, so they will die if exposed to the sunlight.
Decapitation - This would generally kill anybody, but it works if you’ve got the tools, strength, and speed enough. Burning their remains after is advised if you can do it inconspicuously.
SAVING A STRIGOI
Most who become Strigoi, either by will or force, are automatically considered ‘dead’ by their peers and loved ones. An Awakening is never taken lightly and is usually seen as a tragedy or disgrace, depending on how the situation was beforehand.
However, there is a way to restore a Strigoi to what they once were, but unless you happen to know a Spirit user willing to risk their safety, there isn’t much that can be done.
Since silver stakes are almost always infused with the elements, aside from spirit, all you really need is for a Spirit user to stake a Strigoi and infuse the stake with their element as they pierce the Strigoi’s heart. Since Spirit users are the only vampires that can ‘create life’ with their magic, a Strigoi’s soul would be mended and they would be reverted to whatever they were before they were Awakened, whether that be human, dhampir, or Moroi.
Once you are restored, there is no way to become Strigoi again, and depending on who you are, you may die trying. Those who have been restored also seem to age considerably slower. The events of Bloodlines and The Golden Lily somewhat tackle this topic. Another notable event is when Sydney Sage is bitten by one Strigoi in particular. They complain about her blood being ‘wrong’ and ‘tainted’, and this has to do with the earth magic in her Alchemist tattoo. Because of this, a vaccine to prevent Strigoi from being made is then put into development using the same concept of elemental magic.