Broken spear and loot
Eldrian knew he would not be able to think of an answer. So after satisfying his curiosity by having found the reason, he tried meditating. Finding that he could actually now move his mana not just to his head, but also his limbs. Increasing the number of paths from the one he had been practicing with, to five.
Eldrian first spent around half an hour just getting used to the new way it flowed. The feeling of creating so many paths and then sending mana through them, something new and hard to maintain.
Only after getting used to it, and being able to focus some of his attention on other things, did he start practicing with the sword again.
The start was hard, almost like he had never tried this before. He would let slip his concentration and either mess up his attack, or cause his mana to retreat and the pathway he had made to be lost.