Increases Attack for party members by 15% multiplied by the number of remaining enemies on the field when combat begins.
Increases Skill Activation Rate for party members by 1.65x on turn 1.
Increases Damage of Skills for party members by 15%.
Increases Attack for party members by 15% on turn 1.

Yeah she is pretty garbage. I assume she will be buffed very shortly because this girl will bring a lot of discontent from the community.
My guess she will get one more ability. But for her to be anywhere near usefull as a 1st turn girl that 1 time damage buff needs to be at least 50-60% bare minimum if this is what she is supposed to do. Who ever was the person who came up with this girl didnt really consider the overall balance because that skill is utter garbage and about as useless as the shitty 30 Shine drop crystals.

Now if you got her from the gacha for Free ? I wouldnt complain that much. Its still a 6* so the stats are there, and I am sure she will be buffed (no way the JP players will not complain about this). Now If that damage got buffed only to 30, but she received Debuff, that would be something to consider. As long as you dont have at least 2 full teams of synergistic 6* doing specific team, any new 6* is usefull.