I simple wait for doing this quest till my hero was level 9 or more ... (on nightmare mode) to be sure to survive ... and first summon my Ghost, he's my most helpful buddy.
On 7th of february 2015 : I start a new adventure in the Divinity world of Original Sin, it's a Fantastic Freaking Fabulous Funny ... it's my All Time Favorite One !
... and first summon my Ghost, he's my most helpful buddy. 
