It'd work a little something like this:
- Beat a danger mission, get a Shadow Shard
- This is a one-time reward per player per cycle. You can't simply repeat the same danger mission to get another one.
- Shadow Shards expire after let's say thirty days
- These are tradeable
- An alchemy machine thing at T3 basil can craft a shadow key out of four shards. A full party can beat a single danger mission and go shadow lair immediately
- Crafted shadow keys last let's say 7 days
- Shadow Lairs given a little something extra to be worthwhile. I don't know, maybe UV tickets or whatever the current lootbox is.
There you go, regular incentive to play Spiral Knights.
Shadow Lairs are cool and don't really reward much (except Merc Demo and Snarby Coat). I wish I didn't have to take out a mortgage to play one.