Some kind of crash


############################################################################################
FATAL ERROR in
action number 1
of Step Event0
for object obj_battlecontroller:

Variable obj_battlecontroller.spellgem(100598, -2147483648) not set before reading it.
at gml_Script_bc_OnAttack
############################################################################################

stack frame is
gml_Script_bc_OnAttack (line -1)
gml_Script_scr_AddEventToStack
gml_Script_bc_CreatureAttack
gml_Script_bc_Turn
gml_Object_obj_battlecontroller_Step_0

Had a Forest Priest and a Noxious Smog alive against 4 enemies, was attacking to hopefully try and salvage a battle, and eventually what I feel like is Chaos Magic now that it was programemd in causing a crash.