What's so scarring about it? It's an (obviously edited to fit with the event's theme) image from a sex scene, like a lot of the other event banners.
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[edit] Oh, I just noticed that you can check the status of your charge skills by clicking on your valkyries during battle. Also, panel change skills need to be activated manually, again by clicking on the valkyrie during battle. Changing panels is seriously powerful; the turn you use, all the panels change. The turn after, five panels change. And so on until it wears off. With two or three valks firing off panel changes, you could conceivably go into battle with just one color of valks and just continuously tear into monsters with all six team members.