Dragon Promotion

Dragon Promotion ( 竜変化・命還(ドラゴン・プロモーション), Doragon Promōshon lit. Dragon Metamorphosis: Life Return) is a Compact Regression spell; instead of being confined and exclusive to a single element, it can be utilized by any Dragon who had used Compact Regression to transform into a human guise. Essentially, Dragon Promotion enables the user to transform back into their draconic form.

Description
Dragon Promotion is considered to be a forbidden art amongst dragons; even though many of them wish to return to their roots, the risks involved have caused many to swear off of attempting to do so with this spell. Dragon Promotion works by the user releasing the restraints that Compact Regression forces upon them completely for a few minutes at a time, effectively dispelling it and enabling them to take upon their original form. The release of Compact Regression is only temporary, as spending too much time in their dragon form makes them a relatively easy target in this day and age, but the results are all the same- the moment that the user releases the effects of Compact Regression, they regain all of their former strength, speed, durability, and magical power, at the top of their form once more.

When Dragon Promotion is activated, this causes an instant change in form which blatantly ignores the law of conservation of mass, going from a (comparatively) small human into house-sized dragon in seconds (but hey, magic). Of course, with the change in size, the dragon goes from having the Magic Origin of a human, which is relatively small, to the origin expanding tenfold when the user transforms; as when Compact Regression is active, the dragon's power is cut quite a bit to enable their souls to adjust to their humanoid shape; as a human body cannot fully endure the power of a dragon without breaking down. In a way, Dragon Promotion could be considered a power akin to Dragon Force, albeit in reverse more or less, as it returns the dragon back to their original form instead of transforming the slayer into a humanoid dragon.

When combined with the Dragon power of Scale Up ( 竜段改善(スケイ・アップ) , Sukeiru Appu lit. Dragon Level Improvement), which enables the dragon to undergo an initially temporary evolution into a stronger, more advanced form, Dragon Promotion becomes Scale Up Dragon Promotion ( 竜段改善・竜変化・命還</rb>(</rp>スケイ・アップ・ドラゴン・プロモーション</rt>) </rp> , Sukeiru Appu: Doragon Promōshon lit. Dragon Level Improvement: Dragon Metamorphosis: Life Return), perhaps the most inventive term around. Scale Up Dragon Promotion grants the user a full release from Compact Regression, in addition to dramatically boosting their power to the point that they could be considered stronger than ever before- for those unaware of the "Strongest Dragon Transformation" (最強の龍変身, Saikyō no Ryū Henshin), Scale Up Dragon Promotion is the most powerful spell at their disposal. However, Scale Up Dragon Promotion also quickly saps the user's life force and magical energy for every second that it is active, making it rather impractical to have activated for long periods of time; thus it is best used for finishing attacks.

Trivia

 * The childlike scribble, or rather, a "diagram" was drawn by Tsuruko Sejren in the chapter Dragon Isn't Even a Word Anymore of Daybreak S1, when Rosa Dimaggio was explaining how she transforms into Indra and back again. Unable to really get the magibabble that her friend was spouting, Tsuruko drew a diagram and asked Rosa if it was accurate from what she got out of Rosa's words. Of course, the response was "The hell am I looking at here? I'm pretty sure I ain't some god-damn fish."
 * Normally hand-made visuals are rarity, but considering how deplorably bad Tsuruko's artistic "skills" are, the author decided to spend ten minutes in Microsoft Paint to actually show what the others were confused over. Ironically, Tsuruko's dream is to become an artist.
 * If one has permission for Compact Regression, then they can also use this spell.