Modern methods of Golem construction date back to ancient times and have apparently seen little progress since. In fact, in some ways they may have even regressed.
[LV I] [LV II] When This Spirit Attacks
You may exhaust one of your nexuses to place a core from the void onto the nexus you exhausted.
[LV III] While This Spirit Attacks
When you destroy one of your opponent's spirits via comparing BP, select one of your nexuses and refresh it.