Roboute Guilliman armour of fate question

sry if this is the wrong place to ask this but im trying to find an answer and havent come up with anything yet. So if he fails his come bak roll after he dies, does it mean he is out or do you get to roll every turn untill you get the roll or the game finishes?

You just roll once when he goes down the first time. If he makes the roll he gets back up at the end of the phase. If not, he's toast.

thx alot..!