How to obtain mixed candies?

Mathcat

They can be obtained as a battle result from battling the special Halloween demons (which show up randomly) here or as a possible result from clicking on the purple candy icon on another user's hold (available every five(?) minutes). I have a reasonably thorough battle guide here.

Need site currency? Playing with my hundreds of companions here can earn you a decent amount of both blue stones and reactor stones. Companions may be played with once per hour (total, not per user). If nothing shows up, check back later.

Still on AO3 here - Forest of Mirrors, Dragon Cave, MagiStream, Jelle's Marble Runs, and original fiction.