WERE IT NOT for Matt Wagner and his sword-wielding tales of “Mage: The Hero Discovered,” then ComiXology might not even exist.

Which means ComiXology, in turn, would not be announcing “Mage (Vol. 1)” today as part of its new wave of titles for its Unlimited library.

Starting June 27, the New York-based digital-comics platform will add dozens of offerings to its recently launched Unlimited menu of selections, ComiXology chief executive and founder David Steinberger tells The Post’s Comic Riffs ahead of Monday afternoon’s announcement.

Steinberger was a kid in the ’80s when he discovered Volume No. 11 of Wagner’s Arthurian-influenced adventure series “Mage: The Hero Discovered” (Starblaze) while picking up role-playing cards at his local comic-book shop in Minneapolis. “He was watercoloring the foregrounds and airbrushing the backgrounds, and it was printed on a really nice stock,” Steinberger says of the comics creator, citing the series as a clear window into Wagner’s maturation as a storyteller. “As a 13-year-old, I was so blown away by this thing that I spent the next four years trying to fill in that collection.”

Now, Steinberger says he is passionate about helping other comics fans fill out their collections. (Disclosure: ComiXology is owned by Amazon, which was founded by Washington Post owner Jeffrey P. Bezos. But you knew that.)

Among some of Steinberger’s other favorite titles are “Afterlife With Archie” (“They have redefined the spirit of Archie,” he says); “Bee and Puppycat” (“My nieces love it”); and “Legends of Red Sonja” (“Incredible, mature storytelling from [top] women in the industry”).

Also being added to ComiXology Unlimited — which is unlocked via a monthly subscription fee — are “Gronk,” “Archer and Armstrong,” “Krazy & Ignatz,” “The Mice Templar,” “The Sixth Gun” and “Steve Ditko” and “Vampirella” archives — as well as Magnetic Press titles.

To see the full list after noon today, you can go to ComiXology.com, which launched Unlimited last month in the United States.