Tyranid bioforms effective against the Necrons

• Shield of Baal [Devourer]:

"Beetles fired from flowing schools of tyranids bounced off their necrodermis, smacking with chitinous crunches from the metal. One of the beetles hit something vital in a destroyer, chewing through the necron’s spine. Critical explosive failure followed as the drive skimmer core separated from the commanding section. Shards of metal studded out, thudding into the other destroyers floating around it. Incapable of experiencing pain, none of them even noticed, continuing to fire into the advancing swarms."

• Shield of Baal [Devourer]:

"Vast jaws gaped towards him, hissing and spitting acid. One scrabbled over a warrior to his fore, spiked limbs flailing. Its jaws crunched into his head. Diamond-hard teeth punched through the metal of his skull. Something akin to pain flashed along artificial synapses. A thick, glistening tongue slapped against his face, trying to find purchase. Bladed limbs scrabbled against his body, getting hooked into the gaps between his ribs. The jaws tightened"

• War in the Museum:

​"The gallery is now seven minutes behind planetary time. I dismissed that as a fault, but it’s a temporal bubble, isn’t it? Each time you failed to murder me, you went back, tried again. It’s why the lictor was so effective against my lychguards, but not against those from another time."

• Shield of Baal [Devourer]:

"Something shrieked, something that sounded horribly organic. The screams approached, moving with fierce rapidity. A creature landed in front of them, black eyes staring with malign intelligence. It was bone-white and red. Tendrils stretched from its head, waving like worms or snakes. Great spiked limbs descended from its shoulders, arching over. A tail whipped through the air behind it. The tentacles around its mouth reached out and vile ooze dripped from its pores.The necrons froze. Green light played out from their eyes, scanning and analysing. The creature fixed its gaze on them. It sucked in great breaths, betraying its disgusting organic origin. It shuffled forward, moving in quick hops. Bioluminescence rippled along its fleshy skin, tracing out complex patterns. Parts of the creature’s body blended in with the stone surrounding it. As it drew near to the lychguard, the beast turned its head from side to side. Its tendrils reached outwards. Then it screamed. Hooks shot out from its chest, clattering off the lychguards’shields. ‘What foulness is this?’someone asked. More screeches sounded from far above as the lychguard bulled forward. The creature leapt over the necrons’ heads, twisting in midair. Spiked appendages slammed into one of Valnyr’s guardians and wrenched him apart. He continued to attack, even as he was torn in half. The fallen lychguard used his warscythe and shield to crawl forward, still moving stubbornly towards the source of the attack. But the creature was already moving out of the way, darting towards Valnyr. The cryptek held her staff out, beginning to summon the energy to freeze the animal in time, to halt it in its tracks. She knew, even as she did so, that it was too fast. ‘No!’she yelled. ‘I will not die here!’ Panic flew through her. Buzzing overwhelmed her senses. Shaudukar grasped the creature by the spine. It stalled and mewled in pain, still reaching for the cryptek. The tendrils around its head fluttered as it breathed out. Shaudukar ripped out the beast’s spine with a wet meat thunk. The creature collapsed and flopped against the floor, obscene, pallid flesh glistening against the obsidian. Blood spilled out in a pool. The necrons gathered around it, curious. It was the first glimpse of organic life they had seen since beginning the Great Sleep. It screamed as it died, still writhing."