While not as exciting as their cinematic shorts, Blizzard has been fairly consistently releasing Overwatch comics over the past few months, slowly but surely fleshing out the lore and its characters.
The one released today, however, is a bit special since it doesn't serve as an introduction to a single character, but rather as a brief look into the relationship between Soldier 76, Ana and Reaper, Overwatch's original members with a rather... shady history. You can read the full comic online by heading over here, or if you're so inclined you can get the PDF version by heading over here instead.
I'd personally recommend the PDF version as the online one seems to have some issues with coloring, especially when it comes to speech bubbles given that Reaper is for some reason depicted as blue.
Finally, if you're a fan of Overwatch lore and comics in general, you'll be delighted to hear that Blizzard has teamed up with Dark Horse Comics to publish a 100-page Overwatch graphic novel, as well as a hardcover art book with previously unseen concept art and illustrations. The release date for the comic is set for April 2017, while the art book is pinned for the summer of 2017.