Invasion Bosses

A LOT of these invading bosses need to be nerfed very badly. Mostly the "Rain of" spells and the Totem spells. NO boss should EVER be able to insta-gib a character. It is getting absolutely ridiculous to play Invasion. Some of the bosses need to be buffed a bit, but majority need some serious rework. i have not made it to Merci yet because i run into a boss and get insta-killed. am i the only only with these issues? if so, what am i doing wrong? i had 3k life and 60% DR in act 3 Cruel and got killed faster than i could log out?!?!?!?!?! How is this "Balanced" in any way????