I was lucky enough to get 3 extra Onyx Pearls, extra Scorched Daliahs and Roses and even Rustic Wells from adventuring so managed to complete this event with about an hour left on the event clock. Got the Dark Onyx Dragon, made my first collection from it and guess what? Nothing useful except points and coins. Oh, it dropped some scales too (which I was maxed out on) so, WHOOPY! I have eight other dragons and they all drop scales so what is the use of another scale dropping dragon? At least the Aquamarine Dragon drops Mermaid Scales.
I certainly hope the drops get better otherwise the nights of broken sleep to keep up with the collections required will become nails in the coffin I've been building for this game