In the end, he decided first to master all the 24 pseudo runes and then do all the phantom challenges at once, there were a few reasons behind it, first of all, the moment Axel defeated a total of 8 phantoms, he would ascend to the mid stage of the 1st phase, now there could be lot of questions if he advanced that fast, considering its only been a total of 3 months after waking up from the trial and 1 month spent in Eldarion while being on the trial.
So, a total of 4 months had passed in that case from the beginning of the trial.
His daily routine consisted of attending various classes, spending time with his friends, then forging and engraving uninterrupted, and just one more month later, Axel had mastered all 24 of the selected pseudo runes; now it was time for non-stop grinding. He could constantly fight the phantom figure and achieve the highest level of combat proficiency using that particular pseudo runic weapon on his current level.