SPOILER comming up
-
-
-
-
-
-
-
-
-
-
He's Kagain ; an evil NPC. The nice thing about him: because of his high constitution he regains hit points by himself: quite cheap!

You can travel with him when his badly wounded, and by the time you arrive where you wanne be, he's all healthy again!

The only thing you have to do to keep him in your party is visit the map above Beregost; he'll say the quest is no longer important an will stick with your party.