1 - when a wizard is freezing magda like crazy, her health appears to not drop anymore at a certain point. and that's about the time when she is trying to put up her shield and summon those monsters. but the shield is not up yet. so i don't see why she should be not taking damage. noticed this like several times in the duration of multiple games
2 - i am a barbarian and i begun using the frenzy skill smite recently in ubers and in normal gameplay. it stuns the enemies. and my attackspeed with wrath of barbarian is just a little over 2.00. i've noticed that sometimes while my other teammates are attacking the skeleton king and i am just hacking away at magda stunning her decently. she puts up her shield like she normally does, and summons the monsters. however, after i kill the monsters, usually the shield goes away and you can attack her again. however, this happened twice so far. after killing all the monsters, and i thoroughly checked the entire map to see if any monsters were alive. magda's shield did not seem to go away. and stayed on her until the skeleton king was dead. there was nothing anyone could do to hurt or stop her, she was just a destructive invincible force in the battlefield.