[Phoenix's Tears: a tear of a phoenix that would prolong the life of a dying being by one year if they consume it. The tear can also be a medium of summoning and can be used to forge fire artifacts.]
Even though the last line mentioned artifacts, it was still different from the tears he got at the Runes Apprentice Cup. This was a bona fide tear from the legendary creature, the phoenix. The properties of fire were integrated into it, thus the ability to create fire artifacts.
Arthur had pieced together the information he got about Gala to make an offer she couldn't refuse. As promised, when the night was at its darkest, the spirit appeared beside Arthur and turned him invisible.
He sneakily left his room and went to the library following the map Gala gave him. The night's darkness worked to aid him, not that anyone could see him with the little spirit helping him.