Since the Chaos Formation Technique contained the knowledge regarding the creation of the mana core, magic circle, aura heart, and aura ring, Alister didn't have to ask Zanna about those.
After perceiving the chaos-attributed mana that radiated from the Sea Of Chaos, Alister slowly controlled those chaos-attributed mana to enter his body.
Only those who could perceive mana could control it with their will. Since Alister could perceive it, he could use his thoughts to move the mana toward him and absorb it in his body.
After the chaos-attributed mana entered his body, Alister channeled it towards his abdomen. Following the instructions on the Chaos Formation Technique, Alister compressed the chaos-attributed mana in his body to form a mana core.