I commented based on what I remember, I am not stating that anyone else is wrong just what I remember when I played it last year. No the statement says once a mob is engaged and it doesn't define what that means exactly. Does it mean that if you get proximity agro it is locked? Does it mean it you hit it with a non damaging spell it is engaged? Does it mean any damage and it is engaged? Or is it something like a certain percentage of damage in relation to the health and it is engaged? The only mention of agro in the information we got is about losing it and becoming unlocked.