Arch Imps are to imps as lilim are to succubi - mutant offspring so powerful that they constitute a qualitatively different species altogether, with the lighter hair and tails that seem to denote magical strength among the succubus family. However, arch imps in many cases are oblivious to their own power, and unconsciously scatter bewitching charms like the alice. Any sorcerer foolhardy enough to try and contract an arch imp as his familiar is likely to see the pact reversed with her as the master - which makes dealing with them much like dealing with demons.
The Arch Imp is a mutational variant of the imp that possesses vast amounts of demonic energy within her tiny body. Some imps will mutate into an arch imp if they store up a lot of demonic energy due to frequent sex, but then there are some who are born as arch imps due to having powerful sorcerers or heroes as fathers. Their appearance is exactly the same as an imp, but the coloring of their wings and tail is paler, and their hair is dyed white. It’s a distinguishing trait that can be seen in the Demon Lord and her daughters, the lilim. It’s regarded as an expression that they possess lots of the Demon Lord’s demonic energy, and are closer to her than even among her own kin, the inma. As inma, they possess vastly greater power than higher rank demons such as the Succubus, and are capable of wielding powerful charm spells and have excellent sexual techniques. However, their intelligence is still that of a normal imp, so they’re childish and simple, and they assault human men whenever the desire should arise. Additionally, many of them don’t even realize that they’re arch imps, and will continue to live among groups of imps.
Men afflicted with an arch imp’s charm spells will start to find them unbearably cute, so cute that they want to spoil them. In that state, the men can hardly refuse when they “beg” for indecent acts, and will end up having sex with them just the way they want. In actuality, these charm spells are released unconsciously whenever they tempt a man, so they aren’t aware that they’re using magic, and to them, “a nice man who will listen to whatever they ask, and do lots of stuff that feels good” is extremely attractive. They’ll probably end up liking him in no time at all. The things they beg for from men they like end up becoming increasingly lewd. By having sex with one of the highest ranked inma a countless number of times, men will end up becoming their prisoners from the bottoms of their hearts.
Furthermore, imps are often used as familiars for sorcerers, but when a sorcerer summons an imp, there is a rare chance of an arch imp appearing. if he mistakes it for a regular imp, and attempts to bind a “master-servant contract,” there will be what’s called a “master-servant reversal,” and the sorcerer will end up becoming the arch imp’s familiar.
Due to their enormous demonic energy, arch imps have a power most imps do not, which allows them to change human women into monsters. Since they’re childish, they prefer playing with human children, and if their partner is a girl, they’ll teach her all kind of pleasure games that they themselves love, and will end up turning the girl into an imp so that they can attain more pleasure when they play. If a single arch imp slips into a human settlement, there will probably be a group of imps only moments later.