Originally Posted by
Firegalus
pretty much what other have said here, you want the buff as close to the 20% mark as possible, to get through the burn phases as quick as possible
on heroic with the 6m enrage, if you pop Guardian at the start, it probably wont be of cooldown at the 20%(or if it is your raid dps is going to be too low to kill!), which leaves you with a decision on whether to hold your AW to align it with the totem buff or hold it back even further for GoAK (@5min mark), personally id think aligning with the totem+potion is going to give more dps