With each brief pause in the scale spell, the Rainbow Bridge would reflect the dazzling and mesmerizing glint of a gemstone crystal.
The "Guiding Song"!
This is the top-level fourth-rank magic within the "Great Summoning Technique" in Dragon Language, a unique magic with only one opportunity for use.
Once the initial scale of the "Guiding Song" is played, the special audio frequencies of Dragon Language will proceed to chain resonance, automatically generating the next spell scale until the entire magic is complete.
During this process, the caster need not chant but also cannot chant or summon other spells.
This is a magic that can be completed even if the caster dies immediately, known as the only known uninterruptible special magic in the world.
The "Guiding Song" summons a higher-order natural dragon from the Dragon Realm: the Castle Lion Dragon.
This lineage of natural dragon is also absent from the Aegean Continent, also known as the Gem Dragon.