i think sonic blow is useless in renewal patch..
* Sonic Blow

Regular
Attack Power 440% 480% 520% 560% 600% 640% 680% 720% 760% 800%
SP Cost 16 18 20 22 24 26 28 30 32 34

With Enchant Deadly Poison
Attack power 220% 240% 260% 280% 300% 320% 340% 360% 380% 400%
SP Cost 32 36 40 44 48 52 56 60 64 68