NPCs composing that spawngroup :

a_goblin_life_stealer (50%)

a_goblin_spirit_mystic (50%)

NPCs spawning around that spawngroup :
(Max range : 100)

nurga_66, range=35 (-1920,-1810,25)

a_goblin_arcane_master (50%)
a_goblin_blight_caster (50%)

va_nurga_508003, range=34 (-1921,-1812,28)

va_nurga_508058, range=3 (-1891,-1836,22)