Who's This? The Zorro type on page 26 of Who's Who vol.XXV.
How you could have heard of him: Rod Gaynor's legacy survived in the form of his granddaughter Shelly, who became the Whip that worked with the modern version of the 7 Soldiers of Victory, or at least, the team that was massacred in the #0 issue preceding the series of mini-series.
Example story: Flash Comics #1 (1940) by John B. Wentworth and George Storm
So what's the verdict? Too derivative of Zorro? Or is that exactly why the DC Universe should make use of the character? I mean, he's pretty badass here. I wouldn't mind seeing him hanging around again (or his granddaughter, though the female character with a whip is a bit of a cliché now).
Who's Next? Okay, now we're moving to the last issue of Who's Who's first series. Given it features characters they forgot about after the letter "Z", I dare say it'll prove fertile ground for these posts.