Yeah Mako's Right although the resulting effect is very very good if coded properly
Most people want to use a slenderman as an example so I'll do the same
Say have 8 or so randomly place around the level with unique names
Example
Slender1 at Spawn location 1
Slender2 at spawn location 2
Then using random=x set them to spawn or show based on the result if the randomizer.
Example
Random=1:setifused=slender1,activateifused=1
Random=2:setifused=slender2,activateifused=1
Random=3:setifused=slender3,activateifused=1
and so on and so forth, these actions Ideally should be placed in a script, given to an entity thats always active and placed outside the play area.
Then code the enemies fpi however you like and when its due to disappear either destroy it if you dont plan on calling it again or hide it and cull it if you are.
What I would do is have a variable like globalvar=ActiveSlender, to which you can set the value of the currently active enemy, so globalvar=slender 2, would do a check to see if slender 2 was active so you can always be checking to see if one enemy is active to prevent the script spawning a duplicate elsewhere
then when the slender disappears, reset that variable to 0 and in the main script that selects and spawns the enemy only allow it to do so if that variable is set to 0
smoke em if you got em
