NPCs composing that spawngroup :

a_bile_golem (25%)

a_helot_spirit (25%)

a_sepulcher_skeleton (25%)

a_sepulcher_spectre (25%)

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

charasis_103, range=82 (-273,182,4)

charasis_131, range=54 (-263,280,22)

charasis_132, range=50 (-221,296,23)

charasis_135, range=52 (-243,294,22)

charasis_138, range=32 (-189,243,22)

charasis_139, range=40 (-188,222,22)

charasis_155, range=71 (-154,224,-139)

charasis_156, range=85 (-136,242,-162)

a_sepulcher_skeleton (50%)
greater_plaguebone (50%)

charasis_165, range=94 (-226,152,4)