Yeah i did the same i really wanted my only good nutaku unit raven back but i didnt get her...
After spending around 100 crystals on gacha trying to get raven the only decent unit i got was ramii, but after using her now for some time i do not mind.
She is just broken, her attack speed and range is great but what makes her really broken is het attack.
1252 attack for non-awakened lvl 70 unit is insane.
My current strategy is just to get enough deployement points drop her in the middle of the map and laugh while pushing the speed button.