Aliasing blade_arms → blade_arm
Link to alias

Reason:

Pural->Single

I mostly see this show up on species who have a pair of blade-arms, but I could totally see something having only one arm that has a blade as part of it.

Related aliases:
scythe_arms -> blade_arm (scythe arms are just arms with an angled blade on them)
scythe_arm -> blade_arm (unused, but singular variant)

Hyphened variants haven't been used so far on these tags, but they certainly have shown up on other Underscored tags, so those may merit aliases too.