NPCs composing that spawngroup :

an_explosion (12%)

an_immobilizer (8%)

an_inactive_trap (8%)

a_blast_of_heat (8%)

a_dark_entity (8%)

a_formless_terror (8%)

a_magi_construct (8%)

a_null_field (8%)

a_wave_of_cold (8%)

a_wizard_construct (8%)

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

necropolis_69, range=79 (1153,-548,-255)

a_Chetari_Deathbinder (50%)
a_Chetari_Dustshaper (50%)

necropolis_100, range=56 (1134,-681,-255)

a_Chetari_master (50%)
a_Chetari_seeker (50%)

necropolis_102, range=94 (1182,-543,-255)

a_Chetari_master (50%)
a_Chetari_neophyte (50%)

an_idle_trigger_190155, range=67 (1174,-570,5)

an_idle_trigger (100%)

necropolis_112977, range=72 (1176,-565,3)

a_pile_of_bones (100%)