Playing agains necrons

Hi, I'm quite new to this hobby and I play agains my friends who are playing thousand sons, Tyranids and necrons. We usually play 2v2 games each 1000 points armies. It just me or necrons are too op. My 435pt angron is in combat worse then his 300pt nightbringer who is unkilleble, what I'm supposed to do with it ? I know that angron can respawn but I roll 4 blessings for it and non of them were even close. I would expect more from primarch.