NPCs composing that spawngroup :

#Pulsating_Pool_of_Magma (50%)

a_burning_mire (50%)

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

soldungc2780172, range=95 (473,-408,4)

imp_vanquisher (100%)

soldungc2780194, range=91 (453,-364,16)

imp_guardian (50%)
imp_guardian (50%)

soldungc2780196, range=38 (543,-380,16)

imp_guardian (50%)
imp_vanquisher (50%)

soldungc2780198, range=60 (588,-381,14)

a_blistering_horror (50%)
a_smoldering_abomination (50%)

soldungc2780203, range=70 (611,-329,11)

a_conflagarant_terror (100%)

soldungc2780216, range=63 (484,-368,17)

soldungc2780221, range=64 (598,-310,2)