My brothers Venerable Dreadnought killed the Fateweaver in one shot from his Lascannon. He hit, he wounded, the Fateweaver failed his 3+ invulnerable, he re-rolled it, failed again, took a leadership test, failed, and away he went. Then came the other player basically reading the whole codex before he would accept that it happened. For me though, my Vets in the Valkyrie with Bastonne blow up just about every vehicle they shoot at the first time. Done it to plenty of Land Raiders and everything else.