Many LLMs are surprisingly good at using specific named authors (rather than just example texts) to evoke a style, so you could try "in the style of Jorge Luis Borges" or "…Douglas Adams" or "…Robert Anton Wilson" – whose surreal/absurd/fantastic styles could be fertile seeds.

(If not already familiar with Borges, definitely check out his 'Tlön, Uqbar, Orbis Tertius' and 'Library of Babel' as inspiration.)

While "each article written once" an interesting & useful constraint, a Hallucipedia that evolves like Wikipedia, with revisions "towards" some level of inter-article agreement, or even shows scars from edit wars between competing schools of thought, might also be fun.