Like its larger counterpart, the protonic inversal throwing axe is a much more rare version of the standard proton throwing axe, being shortened and balanced for ranged combat. It does 20 more points of base damage than the normal proton throwing axe at the expense of being much rarer.
Protonic inversal throwing axes are classified as "unique", because only a limited number of them exist within the game.
While they have higher damage than proton throwing axes and are the most powerful throwing weapon in the game, their very limited availability (they are the rarest and most limited throwing weapon in the game) hinders their usefulness.
It is very possible to only find less than 10 in the whole game, while at most finding around 20-25, as there is only one guaranteed location to find them and that will only get you 5, while every other location they are found is entirely random, their limited availability is quite similar to the mini nuke, only much more random.
The protonic inversal throwing axe has very high item health relative to most other melee weapons, and as such would degrade very slowly, even though you can only attack once with it as it becomes unretrievable once thrown.
Like the regular proton throwing axe, the protonic inversal throwing axe explodes (only cosmetic) when it comes into contact with a target, providing a logical reason it can't be retrieved.
All cyberdogs are affected by the additional EMP damage done by this weapon.
The technology used by this weapon appears to be similar to the electric weapons created in the Secret Vault by Vault-Tec.
A similar weapon, the protonic inversal axe, is based on the proton ax of Wasteland, the 1980s game which is considered to be Fallout's predecessor. The protonic inversal throwing axe likely has the same origin.