Red Ginger ; Paper only verdict.
yea, I don't have her so it's a only paper verdict.
First her pros.
Her passive buff is very strong, the +30 atk & +15 skill dmg is no joke for the enemy.
She has advance activation type passive which can produce skill use by its level.
If she has lv 5 active skill, combine with at least 2 knights that also has activation passive she will use her skill a lot.
Also her active skill can heal her HP, so she's durable more than she should.
Oh, she can counter too.
And her cons.
She has 1 panel passive the party speed, that make her lost 1 passive slot.
It maybe not big deal, but in Whale mission that not require speed this skill is no use.
yea, some may say...
hey you can put a knight that has +atk by speed party to get benefit from Red Ginger buff.
Ummmm... it's not so easy to find that knight since I believe we have only 3 rainbow knight that have it.
No no no, I won't count Kinsenka no I can't.
Another thing, she can counter but can't dodge.
That mean her counter is not effective than it should.
Even she can heal herself with her active skill, but without extra help from teammate she may faint.
So paper only verdict : A.