So I figured out why the blade of crota was in the cosmodrome. It's kind of a public event where text shows up. It says minions of crota are preparing a ritual. Then after some time it says the blades of crota have invaded this world. This was at the regular cosmodrome spawn location. You go to where the 3 hallowed hive are and you'll find a Blade of crota knight. Kill it and it will drop the relic sword. I'm not sure what the purpose of it is. Didn't get anything for killing all the hive with it and it exploded afterwards. Have a video uploading of it atm. Edit: So this is also happening on the moon apparently. Don't know how hive would invade their own world though since Tyrian and the Traveler already "gave" it to them. Things To Try: - Use a jackolyte - Kill minion of Oryx in forgotten shores with the sword