Super mystery boxes can be obtained from various sources in RuneGuild, but are mainly obtained from upgrading regular mystery boxes at the magic well. The box contains a random selection of useful items, with the rarer loot of the regular mystery boxes now being more common.
Upgrading
Super mystery boxes can be further upgraded by throwing them in the Magic Well at home. It has a 20% chance to be upgraded into a ultimate mystery box, which contains an even better selection of items.