• Nirai On 2017-03-31 22:24:23
• After rank 4 actually - no. On screen you can see how many upgrades you need. Each upgrade from 0 to 3 rank need only one thread (common ones). From 3 to 6 rank you need 5 threads (medium ones) for each upgrade. And from 7 to 9 you need 8 advanced threads for each upgrade. If my calculation is correct upgraiding it from rank 4 to 5 will take about 7-10 month.