I don't know if this is what you mean, but if you have a level 90 that can boost, then you can do something like this: wow1 (in the new bnet account) invites wow2 and wow3 and the rest however you want, as long as wow1 is linked to at least two accounts. Have your level 90 boost wow2, wow3, wow4 and wow5 to level XX, then have wow2 and wow3 grant levels to wow1. Since they get one level to grant for every two they earn, wow1 will be the same level as the rest of the team. It should be the fastest way to level a team of five characters to 85. Once you are done with one team, rinse and repeat. Then make your way to Dawn's Blossom in the Jade Forest, gear up your teams with class and spec-appropriate ilvl 372 green gear from the merchant, and you're ready to grind to 90 in whatever manner you want.
Connect With Us