Nye at first was declared that he can't use any elemental magic by a royal mage, but the truth was he couldn't use any other magic because of his unique skill Ars Daemonium, it was a skill that loathed holy attribute which was needed to use basic elemental magic.
When Nye was 2 years old he would try different ways of using magic but always fail at it. He would always think what was the use of an ability that he couldn't use. After many failures he was one day able to use the skill.
"My master, i have long awaited this day when you would call your servent", said a certain person rising from a dark hole, "Forgive my rudeness my master, my name is Asmodeus, one who rules over lust.", he said facing towards Nye, who was shocked to the sight of demon thinking why would a higher demon ever call him master, after which he remembers that his powers were given to him by the Goddess of demons so it started to make somewhat sense to him. Adding to the previous words Asmodeus began to tell Nye how his unique skill worked and how he could summon other demons as well as use their powers as he wished.
After sometime, Nye sent Asmodeus back and said him '"I'll be summoning you once I feel like it, so teach me more about the abilities I have.", smilingly to which Asmodeus replies "as you wish my master."
Just after Asmodues goes back to hell, Nye recalls what he said to him, to summon higher demons he needs to increase his level and perfect his imagination of what kind of demon he wants to summon, and after he summons a particular demon he is able to use their powers as he wishes even after they go back to the hell, excitingly to this info Nye says to himself "now we are talking, I now need to level up fast but in a body of child it might be hard so lets just wait for 10 more years till then I'll have Asmodeus teach me everything about dark magic and Ars Daemonium."
Nye kept summoning Asmodeus and got to learn how elemental magic worked and how dark magic was different from it. He also came to learn about his unique skill. He had the ability to summon the 9 kings of hell but before he could summon one he had to complete a certain criteria. First was level and second, most important one, was the ability do discern between the emotions that those 9 kings ruled over.
As why he was able to summon Asmodeus was because he had fulfilled the conditions, when he was still in his original world he had never gotten any chance to get intimate with any person of the opposite gender, his lust was already at its limit, so he was able to summon Asmodeus the demon who rules over carnal desires.
Many days and nights went and it was finally 12th birthday of Nye, during the course of these years he practised hard and was able to summon two more demons now, namely Belphegor one who rules over gluttony and Mammon one who rules over greed. Their powers whom which could he use freely without any restrictions already made him a person who could single-handedly destroy whole city without breaking a sweat.
During the span of these 10 years, Nye's' new family had a new member, now that certain member was trying to get Nye out of his room for the birthday celebration, "Big bro, come out or I'll eat your birthday cake", she said with an exciting look in her eyes, replying to which Nye said, "I'll join you in a bit after dressing up properly, till then be a good girl Ilse", to which Ilse replied, "You better not be late because there are some special guests that you might want to meet before they go back."
Nye already knew she was talking about the King, Queen and their children who were said to have high affinity with elemental magic. Nye had already forgotten about the incident that happened 12 years ago, but he still had those lingering regrets why did they never give a chance to show what he was capable of, now that it was finally time for them to meet, he wished to at least fight on of their kids to cool down his greed for power and hunger for a small revenge.