The Secret Files of Dr. Drew -- Elusa

Though Will Eisner was always the guiding force behind the Spirit (except for his stint in the army), many other artists and writers worked on the series. The best of those teams was probably Jerry Grandenetti (artist) and Jules Feiffer (writer).

Here's a sample from Grandenetti's Fiction House's Rangers Comics. The story doesn't make a great deal of sense but the art is extraordinary.