"To be able to summon the creatures of the five elemental planes, you must have a deep knowledge of the School of Summoning and also have the ability to be able to manipulate the boundaries between the Spirit World and the material world," said Professor Whitaker.
The lecture continued as the old professor explained the intricacies of advanced summoning magic.
"Spells like Summon Elemental and Summon Beast, both of which are Rank 2 spells, act as bridges between the material world and the Spirit World," she continued.
"It allows the creature to be summoned to our world for some time. Students, please note that the creature's strength, the number of creatures, and the duration of summoning are all related to the caster's mana reserves."
"In other words," Professor Whitaker added after a brief pause. "The greater the mana reserves, the greater the effects of summoning magic."
