regarding archers, I'm not sure how many times they can restore their life, but they are brutal to face.... especially in a group fight. I've only fought them once, but each time you faced them, they shot arrows that dealt ~50 dmg to several people on your side before hitting.... I remember their spell hurt a ton too. It's been a while since I fought them, so my memory isn't perfect, but it's definitely not a summon I'd like to face again.