You focus your magical senses on a heavy earthen ballista.
The earthen ballista has a definite magical pattern, which apparently holds it into its shape.
You recognize the pattern as Elemental magic.
It is apparently a manifestation of Earth Manipulation magic from the Magnetic Ballista spell.
You feel as though you could LOAD the earthen ballista, readying it for another shot.
Also, you could RUB this earthen ballista to halt the magnetic pulse effect created when it fires.
This earthen ballista was created by you.
You sense that the earthen ballista is sustained by a magical pattern which should remain intact for about 19 roisaen, unless the ballista is adversely affected by the weather.

Any chance when you focus on the ballista you can add in that 'break ballista' removes it?