I got slammed with a moderation before with a topic with a similar premise for spoilers. It was to be more on the safe side.
Anyways, the third one was indeed Smokescreen. It was a variation of Flash and Sand-Attack and learned by a majority of Fire-type Pokemon.
I will update it in the next post.
I think you need to learn the definition of "majority." It means most. It doesn't mean a lot. There are more Fire Pokémon that don't learn it than do. 10 Fire types learn Smokescreen. By my count, there are 49 Fire types total. That's not a majority. That's actually a vast minority.
I meant more along the lines that out of the Pokemon that can learn it through leveling up (which makes 17 Pokemon), there are 10 that are Fire-type. I will try to be less ambiguous in the future though, so that was my fault.