svalinn vs rare +2 minion shield

which one is better for "survival" but also damage over time... cause sometimes certain boss is really hard they do kind of "aoe".

would this svalinn basically make me unkillable?

Depends which content you want to run.

Svalinn is really good for T16-T17 map bosses, but for ubers not really. Also, with Svalinn you want to avoid the map mod which reduces your block chance, so it's not great for farming unidentified/TwistOfFate/risk scarab maps.

ok thanks