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. 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.
They may be found on Number 27 and Number 34. They can carry up to 10 protonic inversal throwing axes each which is more than anywhere else, but, again, this is random.
They can also be found on the corpse of the legendary bloatfly, though this is a random occurrence.
Notes[]
Protonic inversal throwing axes are classified as "unique" because only a limited number of them exist within the game.
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 of them while every other location they are found is entirely random, their limited availability is quite similar to the mini nuke, only much more random.
Behind the scenes[]
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.