"Yes, exactly. The instructions here allow to create a... simulation, of the spell-casting neurons of the brain. A mirror of your own skill that is programmed with the spells. And now you are bouncing the lit torches off of a wall without extinguishing them, catching them and returning them."

"It would require unparalleled skill even without the energy cost of the simulation. Which is astronomical, and ongoing."

(Palamedes chuckled at 'unparalleled' when she said that to him. Nerd jokes.)