>>544070812
If you wanted to change quite literally the entire WoW storyline up until this point then you can do so just by changing one event: Cairne's death. If Cairne hadn't been killed in Mak'gora by Garrosh thanks to Magatha's poison, then the entire past 15 years of WoW changes completely. It is quite literally the most important event that's occurred in the WoW timeline, and it isn't even close. Which makes it ironic because it happened in a book.