BaronMind said: Skribulous did something like that in his Super Yukkuri Taisen story.
I haven't abandoned SRT yet. I've put the story in the backburner since I've lost the drafts, but I'll get back to it soon enough.
And it's not exactly imagination the Yu-engines in my setting mainly run on, but the yukkuri's emotions that drive it (with the yukkuri's "uneasiness" aka. suffering and despair as the easily harnessed ones). OTOH, the weapons are "created" by the yukkuri's imagination, or specifically "belief in their own power" so it's still technically correct.