Spiral Knights & Admins,
This is just an idea I had floating around, starting from a goal I had set up a couple days ago for myself. The original idea was to save up as many minerals as possible, and flood a gate at the last second, to have a gate set up to all one element. A friend was willing to help, but said something that got me thinking about an event you could do once a month, year, et cetera.
The [Time Descriptor] of the Element!
Why not, once a month or so, have a special event set up where each gate corresponds for one element for a few days? You have a Fire Gate, a Shadow Gate, et cetera. The enemies in the gate are tougher, quicker, and meaner. At the end of the gate you get a few special ingredients that correspond with a specific elemental costume or piece of equipment; that can or can not be traded. For example, the Fire Gate could have the ingredients to make a costume bit that looks like a Vog helm or such, where the hair in the back are whipping flames ... the Ice Gate could have ingredients to make a costume bit that has Ice spikes sticking out like the Ice Jelly ... et cetera.
It could be a costume bit, a piece of armor equipment, trinket, or even weapon.
The bosses couldn't be special variants that represent there element, for example a Snarbolax on fire ... that leaves like a 10 second trail of shadow fire when he passes underground (cutting allies off from one another, or separating the entire team from the rest of the open area). There are a lot of possibilities and ways you could go with it.