[Karinya]

So the max exp per week you can get out of it is actually less than empress, but only if you were going to use *all* the charges on your empress, which I for one hardly ever do.

If the "use before logout" and "last charge doesn't set timer" tricks both apply to emperor you could get 6k bonus exp in one session (or at least one day - you need a break in the middle to trade in the empty ring for a full one).