Athena said:
Fletchling was used in all 3 Gym Battle's we've seen so far. It won the initial match against Viola's Surskit (after the Surskit had been weakened by Pikachu) but was KOed by Vivillon. It was KOed by Vivillon again in the rematch. Fletchling also went up against Grant's Tyrunt and weakened it but was KOed.
So, he did get a KO in, but only in a failed battle. Both times Ash has acting beaten the Leaders, Fletchling's gotten assists but not KOs.
I do think we need some kind of action by Fletchling before it can evolve, though. If it was going to evolve base on its actions in the Gyms, it would have done so already. Hopefully we'll get some more action from him before he evolves, and I think we have the time for that to happen. Perhaps he will evolve in Ash's eventual Gym Battle with Korrina.
I guess. Ash will probably send out Hawlucha first against Korrina's Hawlucha, but since Korinna has had hers for longer, Ash's gets KO'd.
Ash then sends out Pikachu and manages to KO Korinna's Pokémon, because of the electric type weakness it has.
She then sends out Meinfoo/Machoke and Pikachu does a lot of damage against it, but also gets weakened a lot.
Ash returns Pikachu and sends out Fletchling, who then KO's Meinfoo/Machoke.
Korrina sends out her last Pokémon, Lucario and Ash returns Fletchling for Pikachu.
Pikachu gets KO'd by Mega Lucario.
Ash brings back Fletchling, who suffers a huge blow, but then evolves and its increased speed and fire type attack, Flame Charge is enough to knock out Lucario.
This is how I think the battle should go. The next gym is where Hawlucha shines, as Ash probably won't use Fletchinder for it.
I just noticed how three of Ash's Pokémon are weak to electric type moves. He needs to get a ground type to make up for it. Too bad there's none in Kalos that Ash would use.