Mathematician Devil's Challenge

Have you heard about the Mathematician Devil? No, no. He's not some legendary evil figure, but a wandering mathematician. He calls himself the Mathematician Devil. He challenges himself against famous mathematicians wherever he goes and steals people's entire fortunes when he beats them. Well, he has challenged me this time and bet on my deck of Hero Cards. I can't and will not lose them! They're my entire fortune! But I can't solve his problem, either, because it's too difficult. I will have to end up using the ace up my sleeve. I need the Soul of Mathematics. With its help, I'll take the Mathematician Devil down at once! Hahaha. But in order to summon the Soul of Mathematics, we need one Falchion where the soul will descend. The weapons merchant won't sell one to me because I'm underage. You buy one and go to Summoner Altman East of the central plaza.

Look, the Mathematician Devil only gave me three days, so stop wasting time. Get a Falchion and take it to Summoner Altman east of the central plaza.

Welcome. I already heard the story from the Genius. He told me you would come. Give me the Falchion. Using weapons during summoning is an ancient method, but so is using mathematics. What is the Soul of Mathematics? It basically refers to the souls of all those who've been researching the capacity of magic since the ancient times, their intellectual identities. Well, good job. Please wait here.