Quote from Rezzahan »The legend rule is a state based action and those are checked right before a player would get priority, even before any triggers waiting to be put on the stack are put there. So the duplicate legendary permanents are dealt with before you can even choose a target for the fight (you do that when putting the trigger on the stack). If the death of the legendary permanent causes a "dies" trigger, it joins the group of waiting triggers, so when the SBA checks are finished, it is among the triggers you can order as you see fit, so have it happen before or after the fight trigger. (Though the actual fight will only happen, if the legendary creature is still around to do the deed.)
So in short, first the ETB ability triggers, then the legendary creature dies, then you put the dies trigger and ETB trigger on the stack in the order of your choosing.
Yeah thats what I thought.
Thanks for the clearn and concise answer!