Magda is the ‘midboss’ of Act II of Diablo III, and I’m sorry to say that she’s not all that terrifying of a boss. She is very challenging if you reach for an achievement, but otherwise, there’s nothing to commend her as exceptionally hazardous. That said, she seems to be present more for cinematic purpose than anything else- which is something I can totally get behind anyways, what with the quality of work put into the world of Diablo, especially in this latest installment.
Magda’s fight takes place in an arena with a rather annoying floorplan full of obstacles- four pits, four pillars, and a few chunks of wall. These are more of an obstacle to you than to her, which can up her challenge rating if you find you need to evade her reach.
Magda herself has the illusion of four ‘stages’, though strictly speaking, they aren’t really ‘stages’- they’re just points at which she changes states. Magda’s two states, however, are distinct and can be very destructive if you’re not ready for them.
Magda’s default state has her floating around and throwing masses of hell butterflies at you. These projectile masses of insects will injure you and will heal her to a point- and while they are slow-moving, they will turn to follow you, so if you’re going to avoid them look forwards to a lot of running around. They also ignore the pits and obstacles in the arena, making it a serious chore to beat her while not being hit- good job on that achievement, it’s really satisfactory to get.
If you get up in her grill, so to speak, she’ll smack at you with her stick, but she’ll usually try to float away as well- and getting close to her gives her carte blanche to butterfly you all she likes.
The interesting point of Magda’s fight comes when she reaches 75%, 50%, and 25% health- she’s ‘locked’ to stop at each of those points, so you can’t avoid her alternate state.
This state is an invulnerable one- but it has a catch. Each time she turns invulnerable, she summons an increasing number of morningstar-wielding demons (three, four, and five, respectively) that will come after you in melee and smack you around with knockback attacks. In order to break her invincibility, you need to kill off these demons.
Having an area attack, particularly one like Cleave with the explosive death rune, makes dealing with these creatures very easy, but if you’re not ready for that, expect a serious pain in the keister as you get knocked around the arena by the summoned demons while her butterflies continue chewing away your life.
Really, that’s all there is to Magda- she can be challenging, but with just a little foresight that challenge is never going to reach a fatal level.