Blizzard offers a reminder that the next patch for Heroes of the Storm (possibly coming tomorrow) will include rewards for players who also own Diablo III, as the Diablo hero will be a free reward and a Malthael's Phantom mount will be a Season 4 incentive. Here's the deal:

Immediately following the next Heroes patch, any player with a Diablo III license on their Battle.net account will receive the Diablo Hero in Heroes of the Storm for free. Simply log in to Heroes of the Storm to claim the Lord of Terror and start unleashing hell on your foes. Don’t wait though— this offer ends at 10:00 a.m. PDT on September 8!

The cross-universe rewards don’t end there. Diablo III players who reach level 12 in Heroes of the Storm will also receive a unique pennant and portrait frame in Diablo III for PC and Mac. In addition, reaching level 70 with a Seasonal Hero in Season 4 and beyond gives you the shadowy Malthael’s Phantom mount in Heroes of the Storm!