Can you recommend me some megaWAD made by a single person, with some downright weird, unconventional and needlessly complex level layouts? Same for Build and Quake1 - what are they called? mini-campaigns or something? Anyway, again, one author, labyrinthine, weird, needlessly complex (moreover, this complexity needs to be directly related to gameplay! fancy backdrops don't cut it!), "what did he even mean by this?".
In other words, anything similar to Petersen's levels, Plug'N'Prey, HeXen1, Redneck Rampage 1 or, arguably, Mysteries of the Sith, I guess?