execute if score count_creeper darkmobs matches 0 run data merge entity @s {Health:666,Tags:["not_mob1"],ActiveEffects:[{Id:11,Amplifier:1b,Duration:99999}],Attributes:[{Name:generic.max_health,Base:666}]}

scoreboard players add count_creeper darkmobs 1
execute if score count_creeper darkmobs matches 1.. run scoreboard players set count_creeper darkmobs 0