Flash Gordon: The Tyrant of Mongo (Sundays 1937-1941) is the second volume in the collected Flash Gordon comic strips by Alex Raymond and Don Moore. Some things changed and some things remained the same. In the span of time covered by this volume, the dialogue moved from balloons to borderless text with lines drawn to the speaker to standard literary dialogue with quotation marks and written indications of who spoke (e.g. "That scream!" says Flash, "It sounded like Dale!"). The skin color of the ruling people of Mongo (as well as the rebels of Arboria) continued to fluctuate, eventually settling on the same shade as Flash, Dale, and Dr. Zarkov by October 1938. Coloring varied in consistency from 1934-1938 as Alex Raymond was responsible for penciling and inking, but "the drawings were colored at the syndicate office." One notable mistake included giving Flash dark hair (4 August 1935).
The themes of mercy, forgiveness, jealousy, betrayal, freedom, and tolerance continued to be highlighted, with two unstated questions looming in the mind of the reader: Will Ming be toppled; and will Flash Gordon, Dale Arden, and Dr. Zarkov ever see Earth again?
I daresay the Flash Gordon comic strip steadily improved with every year as Raymond and Moore refined their styles. The frame count decreased, but the details in art and story increased. I read this volume much more rapidly than the first, and I suspect I'll finish the third sooner than I'd like, which is regrettable since it marks the end of Raymond's involvement.