Akuma no Tousen :D
demon blade in Japanese is akuma no tsubasa
ma o
γγΌγ―γγΌγ’γ³
ma o
Furasshu no akuma
Hi no akuma
aoi akuma
'Beautiful demon' would translate to 美しい鬼 (utsukushii oni) in Japanese.
ryu no kiba
youkai, onii, bake-mono
鬼 /o ni/ is a good Japanese equivalent for what you are looking for.
Ookami means wolf in Japanese and yasha means demon in Japanese. Ookamiyasha means wolf demon in Japanese and yasha ookami means demon wolf in Japanese.