Phazers need to be bulky due to the lowered priority of phazing moves. While Noivern doesn't lack bulk (85/80/80 is respectable), it simply doesn't have enough bulk to be an effective phazer like Hippowdon, Skarmory, bulky Dragonite, or even Throh.I don't know if this has been mentioned, but Noiverns problem is that it just barely doesn't kill the enemy Poke that it should. with that odd spk stat of 97. If that's the problem then I was thinking he'd team up really well with Spikers, and Stealth Rock setters (Ferrothorn). Seeing as how he is extremely fast and learns Whirlwind (!)... The damage he lacks would be made up and then some with the right entry hazards! as he is can almost pick and choose what to KO and what to just Whirlwind away. Unfortunately he doesn't have dragon tail to phase out ghosts, but he does learn shadow ball. and he uses it very effectively.
If Noivern runs Whirlwind, it loses coverage or power; if you're using Noivern to secure OHKOes or 2HKOes, it can't afford to lose either of those. Your best bet with this idea is to pair it with Ferrothorn or Forretress since they can set multiple hazards and have good defensive synergy with Noivern.