Kivan is the ranger lingering around High Hedge, west of Beregost. He'll join you if you agree to hunt bandits with him. (I've read numerous times that he can only be found at night, but don't worry about this, he's there during the day too ~_-) My opinion on Kivan is mixed, he's a great archer, but Coran is technically the better of the two with his dexterity. I do not suggest using Kivan as one of your replacements for Xzar and Montaron for one reason: once you boot him from your party, he stays gone for good, no ifs ands or buts about it, he just leaves. (I'll elaborate on party forming in the tips and hints section) Personally, I like Kivan, he's a great addition to your party, especially if you're going for all good and/or neutral alignments, so long as you never want or need to boot him, and seeing as there are still a great many characters to find, I suggest holding off on him awhile.