향기로운 꽃을 찾는 내 나비가 되어줘요, 그대.

- 향기로운 = fragrant, of a pleasing scent.  향기로운 꽃 = a flower with a sweet scent.

-  [향기로운 꽃을 찾는] 내 나비 = my butterfly [searching for a sweet smelling flower].

- X-가 되어줘요 = become X for me.   (X-가 되어 = become X;  V-어 줘요 = do V for me)

So it can be translated as :  My dear, please be my butterfly looking for a sweet smelling flower.