Originally Posted by Roentgen

The reward is "SR or Higher Guaranteed Gacha Ticket" for patrons of IW.

Within FKG-verse, it's generally for getting the event girl (Mirabilis) as well as maxing her skill and equipment slots. She'll be given at the end of the event (after 2 weeks, that is).

Originally Posted by Corintis

The Fireworks collected is like a type of currency that automatically gets cashed in at the end of the event; more Fireworks = better rewards. The rewards list is included in the attached pictures on the post header, or found by checking the "Event" and "Details" tab on the FKG Homepage.

Ah, I see. Being relatively new to this I was wondering if the shop was broken or something, as every other event I caught wind of had you exchange your event currency there.

Guess I'd better get farming. Even if TBH I don't even care if I get nothing else from this one, drew from the priority gacha once for the hell of it and got Victoria. Only my second 6* too.