yeah we don't have *unitexists script command like rathena
although I am also not sure want to implement or not
because since the monster is set with a variable
upon the monster died, the event label can reset the variable back to 0
EDIT: ... maybe implement it then,
with *unitexists script command maybe the .mobid there can become .@mobid
PS: the script command setunitdata/getunitdata has more than 70% are not functioning, https://github.com/HerculesWS/Hercules/compare/stable...AnnieRuru:34-setunitdata
and its not yet complete