Hello there,
- get your non-legendary 600ilvl cloak, from the 12 runestones quest or from the Irion's vendor if you have allready accomplished this before (alt spec)
- do NOT upgrade it
- get your 5k timeless coins and kill the 4 celestials
- listen to the Irion story, upgrade your cloak with the timeless essence
- your cloak is now legendary AND 608
That's not gamebreaking at all but meh, 500 free valor