If you've never fought Celine, beforehand, I warn you, that damn unit can double or even triple stack lol.
By this I mean, it can allow the enemy team to do simultaneous specials with barely 1 second difference off each even if it has not killed units of your team yet.
So you could experience having a tank use his special on you,then you tanked it with a bomber, then suddenly out of nowhere an attacker comes to snipe it off.
Or you could have yourself be hit by the tank or attacker, then suddenly immediately receives an huge heal from Pansy or whatever the main healer is. (Even managed to experience seeing Harley on full life points get a heal from Pansy because AI had so many skill points it didn't even know what to use them on lmao!)
Even though I have Celine myself (and I tested her on my offensive, still ineffective, but very interesting to see that my enrage bar was at almost 10 without me even getting to notice it a couple of times due to how powerful the effect is), I must admit that the current game meta is ineffective on a consistent mid/long term because of how pathetic the speed to gain skill points is, even with the "ideal" boosts to try and beat set ups with her.
Wouldn't be surprised if more players leave because of the incapability to adapt to it. Non 4* decks are just simply out of the cards now. The effectivity of a free to play deck and a pay to play deck without celine is technically the same against one that has it, which is basically very crappy results.
And it is kind of worrying, because in the top 50, everyone is now using it, spamming it everywhere, like if there was no tomorrow, and combining her with nasty units like Windblade, Twins, Harley or Geranium/Robin.
This unit was one that the game did not need, and that I regret watching her release or even pulling her.
I'm sorry for those who intend to try and sometime go for top 10/20/whatever else in the "active" ranks of this game. You will have it very rough.