Random event that spans SWORD in the asteroid belt or debris field

[Ikea]

i like the idea of making it spawnable (i have never fought this, nor seen it) but i feel like players should have to go out of their way to summon it rather than just "oh shit that's the grim reaper" while wandering the debris field for prefab loot. maybe it takes 3+ players to get along and do something specific?

I'd like this solution if there was some degree of randomness to where people can't do this every round. Could make it tied to a prefab in the asteroid belt, but that doesn't seem too fitting. Ideally there'd be a randomized debris field and it'd be tied to a prefab in that, but until then I think I prefer it just being a random event if it spawns as it both fits the game and prevents people from overusing the loot.