Although the transformation was complete, the promotion was not. Abel still needed to craft a new rank 26 wizard rune. He couldn't make any mistakes while trying. Rather, any wizard who experienced multiple promotions shouldn't be making any mistake at this point.
The three rank 25 wizard runes inside of Abel became liquid that was merged with dimensional force and power of the Will. They then took the solidified form of a pen. Very quickly, three of the rank 26 runes were illustrated.