Europa Boss?

[Niennah]

So, wiki says there's apparently a boss in the Europa system that can appear randomly on any map. Has anybody seen it? What is the sign of it's appearance - is there a cutscene? Does it appear at the beginning of a mission, at a random time, or after main objective has been completed? What missions can it appear on?

[Renathy]

My friend told me that Banshee blueprints drop from a defense mission, randomly.

So, it might be from that. That the boss appears anywhere.

[Dreamwalk3r]

There aren't any boss, blueprints just drop as defense rewards.