One of the uncommon magical phenomena categorized by the Ministry of Magic is something they term a “blessing”, which is a form of magical power received by one person upon the death of another. The term is a little misleading, as these powers are not always entirely in the recipient’s best interests, and some blessings have been considered a curse by their owner. There is no standard term for the person who has received a blessing, though naturally some call them “blessed one” or just “blessed”.
The fae refer to this phenomenon as a “splice” or “soul splice”, which does a better job of conveying what has actually happened. Magic researchers at the University of Atlantis call the phenomenon “soul symbiosis”. The term “blessing of the soul” is only used when a poetic term is desired, as it’s even more misleading than just plain “blessing”.
Cause: Despite some limited studies (some of questionable ethics), little is known about why the phenomenon occurs or how it comes about. All known cases of blessings have had some similar circumstances, but researchers doubt these circumstances alone are sufficient to trigger a blessing, as similar circumstances are quite a bit more common than blessings. A blessing only occurs when someone dies, and it’s always a sacrificial death, the person giving up their life so that the recipient of the blessing may survive. In addition, it has never occurred between people who have never met - there’s always a connection between the dead and the recipient of the blessing. There are no known cases of the dead deliberately conferring a blessing to the recipient.
As an example: the most recent known case of a blessing is the so-called Angel of Nara, a young Japanese girl who gained angel-themed powers when her mother jumped in front of a speeding vehicle to push her daughter out of the way.
Effect: Although the exact cause of blessings is unknown, the mechanism of how they work is better-studied. The names “soul splice” and “soul symbiosis” do a decent job of explaining all by themselves, but basically what happens is that the soul of the dead person, rather than passing on, mutates and grafts itself onto the recipient’s soul. This technically makes it part of the recipient’s soul rather than an independent soul in its own right, though it does retain its unique signature, making the recipient appear to have two distinct souls. The powers granted by a blessing can be practically anything; no two blessings are alike.