What exactly does fictional even mean? I mean, considering Locus Zanaanim is a thing. I suppose the line between real and fictional is blurry, considering reality is a lie. Is the Littlest Excrucian actually an Excrucian? Or is he simply a part of the Lie that masquerades around as an Excrucian, in some sort of ironic inversion?
To be fictional is to exist in a liminal state, bearing the property of fictionality, or rather lacking that quality that defines realness without falling into the unreal. It is, as you observe, a rather blurry line to tread; though a being be fictional in one sense they are not made exempt from the burdens of existence.
As for the Littlest Excrucian, consider: when a fictional character is made, there is a void at their heart. If they are to exist they must have a spirit that is them, that being which bears their dharma. With this in mind, does the creator make the spirit or must the emptiness be answered from without?
And a second question: what is the relationship between the fictional thing and the real thing?