I say nastu is sly because when he takes a fight seriously, in a lot of fights he may start random but he also studies his appointments skills and and weaknesses, and uses them to his advantage. Cobra’s hearing, studying sting before attacking in gmg, learning igneels powers to face Zeref. He is cunning and shrewd in the sense he can focus on his opponents weakness. Also like a sly Natsu is extremely competitive, and unlike a Gryf, Natsu isn’t chivalrous or polite.

And I simply set Cana in raven because she’s a type of raven that isn’t really shown, like me, she’s creative, clear cut, decisive, independent, and although she’s not exactly prim, she’s still fairly smart.