People's Army of Sonoma

What’s the deal with all those crystals from the Halloween quest (especially the blue one)? Should we keep them or ditch them?

You should trade all your red crystals for costumes as Tomas will no longer accept crystals once the Halloween event ends on November 15th. You might want to hold on to your costumes (even duplicates) as they may be of interest to someone else in the not too distant future! You can keep your gold crystals for as long as you wish and summon the Harbinger only when you see fit. There is no deadline on using them. The blue crystals will be of use in the next story arc. They will not be essential, but will definitely benefit to those who have them.

Sakkarah