Atmospheric Inscription Wonder

What's it called? Atmospheric Inscription Wonder (in brief: AIW)

What does it do? It is one of two firework spells; this one (the more elaborate) inscribes the message the caster desires in the sky, amongst light and fire, wherein it is seen by all of the people who may be around (same range of effect as a *shout, it seems). A toy spell, nevertheless it shows a great deal of beauty in its feedback, and it is a wizardly and nicer way of sending messages and doing publicity than just shouting or hiring shouters.

Where is it? It sleeps until learnt in the Spelles of thee Arte of Fyre grimoire, at the Unseen University Library, quite near the entrance.

What does it require? A quill and a torch, both of which are consumed in the process.

What skills do I need? Animating, Fire, Binding, Channeling

Has it worked? A correct output should read something like this:

You prepare to cast Atmospheric Inscription Wonder.
You awaken the torch with words of power.
You summon a salamander from the fiery wastes of the eighth hell.
With the quill, you pin the fiery spirit to the torch.
You draw upon the powers of fire, pouring them into the torch.
A small dot of flame shoots up from your hand, hovers above your head and suddenly flashes brightly, forming itself into an imp.
[firewrite xxx]
The fiery imp grimaces.The fiery imp seems to implode on itself, leaving behind a small dot of flame which shoots up into the sky.

Notes: As you may see, the spell requires a specific command, 'firewrite', after the imp appears. The syntax is: firewrite xxx (the phrase you want to appear in the skies. There's a limit to the number of words).
This part isn’t properly the ‘casting’ but the consequences, and what the caster and those in range see as an adittion to room events and descriptions.
Right above you you see: A small dot flashes up high into the sky
Right above you you see: The dot suddenly bursts open revealing bright multicoloured streams of flame that pour down towards the ground.
Right above you you see: Just as you thought the streams had faded to nothing, they shoot back up into the air, giving a final brilliant yellow colour before vanishing entirely.
Right above you you see: As it fades you think you see the letters “xxx” in the gradually disappearing smoke.

Help information:
Atmospheric Inscription Wonder - Write words in the sky.

Atmospheric Inscription Wonder is a miscellaneous type spell that with the aid of pyrotechnics will write a message of your choosing across the sky.