I see why you're not succesful..

Go full dex, Str dex bird doesn't kill a lot
Max out evasion and focus, they're your buffs, max out break, blast, blind, thorn root and thorn wall. Put one in shattering scream. Don't put any points in restore, meditation, or avian scream, they suck.

Break reduces enemies armor, blind reduces enemies hit, blast is a pure strong attack. Thorn root holds a single enemy in place and reduces dodge, thorn wall holds many enemies in place and reduces dodge. All these are useful

Shattering scream when comboed with blast makes Cruel blast, a combo, which does 2x more dmg of blast. To do this, use shatter, than blast. Keep in mind you need to be slightly close for shatter.
Hope it helped.