The trio then ascended two flights of stairs to Crescius's personal chambers, where numerous odd items were scattered around, hanging from the ceiling, strewn about surfaces, and more. In the middle of all of this was a grey-haired mage with a most dishevelled appearance, partially torn old grey robes half-off of one shoulder, and slightly bent glasses dashing back and forth with the signature odd grin of a madman between various things.
Without wasting a second, Arthur casually took one of his shoes off and chucked it at the mage's head. To Luca and Arcturus's surprise, even in his odd trance, the old mage caught the shoe without looking up before chucking it back much harder. He didn't speak or acknowledge his new guests even after returning the shoe, which once again came back with more strength. A good three minutes of almost choreographed shoe-throwing passed before eventually the old mage couldn't catch the shoe, which smacked him upside the head and knocked his glasses off. The odd glow of madness dissipated slowly from Crescius's eyes as he retrieved the shoe and his spectacles, the latter of which he replaced on his head while irritably chucking the show back, "I'm getting old, I used to be able to go for a good ten, twenty minutes before taking a hit..."
Arthur just put his shoe back on, "We're not in the peak of youth anymore. It's not surprising." After straightening his clothes following the tossing battle, the king continued, "Got your head back on straight, Cres, or do I need to try again?"
"Just try it, Art, I'll give you some really nasty spells if you do." Only these two childhood friends dared ignore their statuses and insult each other like children. Crescius grumbled a little, "I was in the middle of making a breakthrough in celestial magic when you came bumbling in here."
"Celestial magic again? Aside from the Dragon Clan's imperial bloodline and the Ancient Elves, no race can use celestial magic. The stars don't exactly just let anyone use their power." Magic revolving around the powers of celestial bodies, mostly stars, had long been considered one of the most inexplicable yet unparalleled forms of magic. In theory, it was unmatched by any magic, even Luca's inherent Mirror Magic. Nobody knew of its restrictions, or really anything about it other than the bare basics, but Crescius was a madman that often dreamed of bringing this unmatched ancient form back from the metaphorical grave.
"I've finally discovered a way we mortals can use it! Through the powers of astronomy and magic, we can connect to the constellations, instead of to specific stars. We are not strong enough to use individual stars, so we'd need to use constellations instead. For example, if we used the constellation Corvus from the Southern Hemisphere's skies, theoretically, we should be able to call upon and temporarily assume the abilities of the great raven itself." Crescius grumbled a little, "Even if this theory holds up, there are some constellations that should be considered forbidden to interact with as mortals. Draco and Phoenix, for example, or the Four Symbol Beasts in general. Those could be taken as an affront to the Dragon Clan, its deity and the deities that blessed the Divine Beasts..."
After a moment of silent contemplation, Arthur noticed the young Dragonborn also thinking deeply on the subject. On a hunch, he asked, "What do you think about his theory, Luca?" Regardless of the boy's age, he knew that Luca had nearly forty to fifty years of experience and wisdom coupled with his knowledge of a future timeline. If anyone alive was qualified to criticize such a theory, it would be a time traveller from the future with a far greater breadth of knowledge due to the discovery of Ancient Elf knowledge in the ancient fortress.
Without looking up during his deep contemplation, the boy said, "In a part of the ancient library in the fortress, there was an old tome the size of a headstone. It listed each and every star along with any associated constellations and what each could do. The Ancient Elves, due to their heritage as worldcrossers, were already strong enough to interact with stars individually, so constellations were seen as practice methods. For mortals, they would be genuinely powerful. Of course, the stars are fickle and decide whether or not to accept or reject your attempts to interact with them. I believe only one star aside from the sun is strong enough for mortals to interact with at all directly, Polaris. The North Star is also a calm star that never rejects those that wish for its help, which is usually to find their bearings in a terrible storm at sea or hopelessly lost anywhere." He sighed a little, "Unfortunately, most astronomers and celestial magic researchers were among the first casualties of the second invasion, as the Demon God smashed open a portion of the heavens to the north-east, causing a fatal backlash in concert with his return. Thus, there was no-one left that could reconfigure the celestial magics for mortal usage."
Crescius had stopped running around partway into Luca's explanation. At first, it was due to confusion. After all, who would believe a child would know more than him about such a topic. Soon, he had taken on a look of astonishment as the boy explained such things he'd never heard of, not to mention confirming his theory of mortals using celestial magic. It then shifted slowly into skepticism as he glowered at the king, "Is this some sort of stunt, Arthur? Are you making fun of me now?"
"You'd know if it was a stunt if you hadn't rudely chased off my messenger. I issued an emergency summons to you, the Military Commander, and the three Head Guildmasters of the major guilds. It is critical to the survival of our entire nation, and you directly ignored it. Do you think I'm making fun of you just because I can?" A deep aura began radiating from the king, along with the familiar scent of bloodied metal, as Arthur began exerting his great pressure towards his friend, who reflexively released his own pressure, an unfathomable aura of wisdom coupled with the odd aromas of magical materials, clashing in a strange and powerful manner.