Granum Crowns can be obtained from any Corpus Ship tileset after completion of the Deadlock Protocol quest. Within every Corpus Ship tileset mission, you’ll encounter a Treasurer who is guaranteed to spawn within 2 - 4 minutes in a non-endless mission and between 5 - 8 minutes in an endless mission. The level of your mission determines the tier of Crown the Treasurer will possess. Level Tiers are as follows:
0-15: Granum Crown
16-30: Exemplar Granum Crown
31+: Zenith Granum Crown
You can visit the Golden Hand found in Corpus Ships and offer a Crown to begin a Granum Void mission of the corresponding type. Once inside, kill the necessary amount of Errant Specters within 60 seconds to earn rewards. The amount of required kills will be displayed on the left side of the screen, and this number increases by 25 for each extra player in your squad. Your available time can be increased by looting Golden Particles (+5s each) from dead specters, or using a fully charged Xoris explosion to free the 3 prisoners (+20s each) in the area. We recommend a Corrosive built regulators Mesa for killing specters.
Reward droptables are based on the Granum Void tier and rotations are based on kills. For a solo player, they are as follows:
Rotation A: 25 kills
Rotation B: 50 kills
Rotation C: 75 Kills
The fastest recommended missions to farm Crowns can be found here.