Any chance the left plug wire is shorting to the engine? Given that you have adequate compression, fuel in the cylinder, and a spark, some combustion should be happening.
I would try the right side plug and wire in the left cylinder. Put the other plug in the right for testing but no spark plug wire. Turn it over fast and there should be smoke from the tailpipe, especially after adding the compression test oil. Moving the known good wire and plug to the non-functioning cylinder will eliminate internal engine components as a cause if it fires.