Wallace's pure mana was supposedly a good thing. Purer mana implies that the magic spells being cast would be stronger and mightier. This also means that the mana formations and arrays would be more stable or sturdier.
Unfortunately, this also means that the spells which were purposedly made for impure mana would not be possible to use.
This was what troubling Wallace right now. Although he could do the breathing cycle multiple times, he always had to concentrate or be conscious of it as it's impossible to do it naturally.
This will lessen his effectiveness since the new forging method requires him to be capable of doing the breathing method that has reached the 'Natural' state.
'Well, it is good that I've found out the problem this quick.'
He could only view this in a positive way as Wallace wasn't someone who would give up easily.
* the following flashback was the continuation of their conversation that I cut out in chapter 136 at 10th/11th paragraph. it's the last chap of volume 1
Thanks for reading!