[ So strictly speaking, you're all correct.  Using Channel Positive in a fight will heal everyone that's inside the area unless you have<a class="postlink" href="http://www.d20pfsrd.com/feats/general-feats/selective-channeling---final">this feat.</a>Ragnar also has a racial ability that reverses the effects that positive and negative energy have on him, so he's effectively undead for those purposes (incidentally, this allows him to heal himself with the antipaladin's negative energy version of lay on hands).<br/><br/>However, Ambrose is also correct in that this use of channel doesn't hurt him because she would have been needing to channel with the express purpose of harming undead.  You don't do both; prior to rolling the amount you declare whether you're channeling to heal or to harm, and only that effect goes off.  So while Thygor might be uncomfortable, we don't have to worry about accidentally killing him every time Asara heals the party. ]