Levison is known as the legendary summoner and one of the only ones (prior to Erdah learning it) who has mastered permasummon. He founded the Levison Academy of Magics (as suggested by the name). He established the academy before he was even a headmaster there. The first headmaster was said to have ascended to a legendary status. Levison was granted headmaster status when this happened. During his time as headmaster he became an archsummoner and continued into the mysteries of what is now known as the master summoner tier. Upon forming a strong bond with a particular summon, he found a way to utilize this bond to consistently summon them. However, he desired more freedom with his summon. Levison had soon found a way by the means of a summoning crystal. Upon the creation of two of these and gifting one to the summon, she asked to be named. Amy was the first permasummon that Levison had called. Having learnt the lost arts of permasummon, Levison studied up and dug deeper into the lost knowledge in the master tier. He was soon able to permasummon another using a separate pair of crystals. This summon is known as Libeak. Through exparimentation with summoning magics, Levison had also found a way to utilize summoning magics to summon gigantic summons. Having a desire to now call a giant summon into the world without restrictions on their part, he looked further into the lost arts of summoning. While it was tricky with giant summons, Levison had managed to stabilize and properly prepare a pair of crystals for Forokk. Forokk would be the third and largest permasummon yet. The three summons are now part of Levison's team of summons. Levison often calls upon Amy, calls upon Libeak when a situation gets hairy and Forokk when there's a serious threat. However, Levison can call upon any of his three existing summons in casual situations as well.
To avoid gathering too much attention, it was at the point of learning to summon Forokk that he retired as headmaster of the Levison Academy of Magic, which was given such a name upon retirement due to his advancements in summoning magics. It was recently that Levison came across leads that a hard to find tome exists out there with additional knowledge that would teach him how to make and keep a fourth crystal stable with himself. As this would give him opportunity to summon and permasummon a fourth he did research and looked for leads to finding this lost knowledge. As having four summons to one summoner was unheard of, he also trained his magics with temporary summons, so that he could handle four summons at the same time safely. However, summoning a fourth summon was not possible at the moment as he could call upon a fourth, but they wouldn't be able to stay. The ancient tome seems to hold the secret that Levison desires to acquire.