hi, there is a bug if u already did this achievement on your main, just log in with any alt u want to have transmorpg and mount, queue for any battleground or raid finder (tested in strand of the ancients and terrace of endless spring).
in the load screen of the bg or the rf, u will get dced and in that lapse of time u will get the achievements of challenge gold dungeons. even if u have an alt in a realm that no one have done it, u can get the realmfirst instantly.
high risk of ban if u try to get realm first but worth it :P.
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