Sons of Magnus vs Tyranids

Played 2k vs Nids at my house against a good friend. Beakycon mission again. Came down to him destroying a Razorback on bottom of turn 7 to win. I was up on kill points and we both held our capture and control and one seize ground apiece. I contested the last seize ground he got last turn so assaulted the Razorback with Tyranid Prime and 3 Hormogaunts. Prime whiffed then 3 Gaunts got 2 6's to glanced thanks to adrenal glands. Was already immobolized he proceeded to roll double 6's to glance it to death thus winning the seize ground 2 to 1 we went to victory points and he had me by 315 pts