Katoptron Katho Phlegon: Clustered straws, burn out like the Moon (集いし藁、月のように燃え尽きよ, Tsudoishi wara, tsuki no yō ni moetsukiyo?), also known as Κατόπτρων Κατω φλέγον in Greek, is the Noble Phantasm of Archimedes.
The optical weapon used to burn the warships anchored in the Syracuse's shore in Archimedes' legend.
The West European world had for a long time completely forgotten about Archimedes' circunstances (his biography was published around the 5th~6th Century, but there was no mention of him afterward), but he was reclaimed by Ancient Greece's literature and scholarship and became a topic of intense Renaissancist debate and attention.
Among others, a current rumor that was considered a sensational conversation topic was this invention that set the enemies ships ablaze. In the present world, no matter what kind of experiment you do, you can't burn a ship with mirror reflections. This indicates that there was still mana in the atmosphere around the time he was alive.
Archimedes took in not only the sunlight, but the mana around him and developed a Mystic Code exposed to the public as a heat ray.