Gemcraft Frostborn Wrath - Fast Lategame (WL 7800+ Grade 11 gem start) Core Farming (Field A4)

Shadow core farming in Gemcraft FW is a pain, but if you managed to get to the lategame (and I mean LATEGAME; I'm wizard level 7800+, and can start with a grade 11 gem) and still need shadow cores to max out your fancy talisman fragments, here's a very fast and consistent way to do it, offering up somewhere between 1500-4000 cores within the span of a minute or so (with wealthy monsters and maxed seeker sense)