*Kill Cho'Gall in the opening of WoD instead of freeing him, cause he's fucking Cho'Gall and you know freeing him will bite you in the ass later on. The portal still falls.
*Kill Gul'Dan when he's trapped powering the portal, because he's fucking Gul'Dan.
*No more legendary ring.
*Garona's mind control is broken because no more Gul'Dan.
*Cordana Felsong doesn't get corrupted.
*Iron Horde becomes increasingly tired with Grommash's defeats and turns on him.
*Kilrogg takes his clan back to the jungles and is never heard from again.
*Grommash retreats to the now uncorrupted Tanaan and waits for a bunch of commanders to come for him.
Roll credits...