Magic pen.

The artefact WooPil "found" is quite a unique item, in truth, unlike the typical artefacts that have been known so far.

Differences from normal artefacts:

• The pen's effect is not static, it scales on the power of the user.
- Typically, artefacts scale on their own power, regardless of the person who uses them. If the artefact has a 1000 potential, it will produce a 1000x effect whoever uses it, regardless of the person's powers or cultivation.
The pen, instead, will produce a result entirely dependant on the power and cultivation of the user.

• It doesn't absorb the magic energy of the user, but that of the environment.
- Artefacts need to recharge when used and normal ones absorb the magic energy from the person who uses them, in the moment they are being used. That makes them dangerous to various extents, as they could drain a person's whole life force, and it also makes their recharge immediate.
The pen, instead, has a long recharge time as it slowly absorbs the magic energy from the environment.

• The pen has two elements.
- Traditional artefacts strictly have one element and that actually makes them more powerful, as they have a high, concentrated amount of pure and stable magic.
The pen, having two elements, loses a strong amount of its potential for balancing the two elements together.

• It's unclear where it came from.
- All artefacts are trackable in some way: whether they arrived in the world world in the hands of the first who left the Halls, were gifted by the Gods to someone or were in Shiinden, they all have a fame and some kind of history. — Except from those from the bad Gods.
Everything points to the fact the pen itself might be a very new artefact and not an ancient one.

• The pen has very strong limitations.
- Artefacts usually are almost omnipotent for what concern their own power. They usually have no kind of limits, as long as one doesn't try to use them for a different purpose than that they were created for.
The pen is limited even in its own purpose.

It's as if the pen was an artefact specifically thought to be safe for children.