At some point, Zygor was destroyed. Accounts differed as to what the cause of this was and when it happened. According to one account, the planet was destroyed in the war against the Xaranti. (PROSE: The Bodysnatchers) Another account given by the Zygon Broton in the 20th century said his world was destroyed in a "recent catastrophe". (TV: Terror of the Zygons) Another account, given by Elizabeth I who had been posing as a Zygon in 1562, said that the Zygons lost their world when it burned in the first days of the Time War. (TV: The Day of the Doctor)
The vanilla WoW Horde leveling guide you see on this site was originally made back in 2006 by Joana (AKA Mancow, or FuriousPaul). The guides have been tweaked many times over the years to make things "faster". The leveling guides were made because of all the messages I got from people asking me how I was able to level up so quickly on new realms. I was first to level 60 on 7 different realms (3 with Mancow and 4 with Joana), even winning Blizzard's "First to Level 50" contest they held back in 2006.