Ash's Noivern is the evolved form of
Ash's Noibat. It evovled during a battle against Zapdos in which
Ash's Hawlucha was hit and was falling out of the sky.
Ash's Noibat quickly went after
Ash's Hawlucha and on its way there, it evolved and managed to rescue it. As a result of evolving, it also learned the move Boomburst which was instrumental in the battle against Zapdos and defeating Team Rocket's mecha which was trying to capture Zapdos. Once Zapdos realized that
Ash's Noivern wasn't actually trying to hurt it or capture it when it protected it against Team Rocket, it was thankful and discontinued its aggression towards
Ash Ketchum.
In the first match-up in the 2nd 3-on-3 battle of
Ash Ketchum vs
Sawyer,
Sawyer's Doublade was paired up against
Ash's Noivern. Despite using Iron Defense multiple times to tire out Noivern, it tried to take advantage of a chance it thought it had but it backfired as Noivern used a combination of moves in the air to defeat
Sawyer's Doublade.
Sawyer's Clawitzer was sent out and its Dragon Pulse directly hit Noivern before it could finish launching its attack and knocked it out of the match.
Sawyer's Salamence was revealed in the Kalos League semi-finals as
Sawyer's fourth Pokémon and it first faced off against
Ash's Noivern. The semi-final battle was quick but well balanced. The two ended up knocking each other out in a draw.