He died in my first playthrough too. My party killed him when he aggroed after the fight at the gate. At first I wasn't sure if he was a potential companion, so I went and took another look at the promo art... yep. Oops.
There's a trail of breadcrumbs from Zevlor to Kagha to Zevlor to Wyll that will point you in his direction if you're not the "talk to everyone, explore everywhere" type, but like all True and Authentic Gamers (TM) I gotta poke my character's nose into everyone's home and business.
