Coolex
I don't under that why Rudeus (Oldeus) hasn't tried to create his Magic-Armour till now as per the Original story, Oldeus's Magic-Armour allowed him the power of God-Rank Swordsman for almost half-a-day (12-hrs). But now, Rudeus (Oldeus) has almost 10-times the Mana-capacity then before thus if he creates the Magic-Armour now then he can continously use it for almost 5-days, obviously with a combo of his Foresight-Eye & Magic-Armour, he'll be able to finish off his Opponents way too easily.