I sent an ask a while back about my scyther, and it seems like the situation’s getting worse… just when I was at the point where I could leave her alone with flareon, I stepped out for a few minutes and he was literally trying to attack her! He’s a bit feisty but not to this point, and I honestly don’t think she provoked her because she’s normally very well behaved… what should I do?

Yes, this would be why it’s important to keep a close eye on pokémon that seem to have a tense relationship. One thing I’d forgotten to mention in the previous answer (for which I apologize) is that sometimes, it’s not a matter of type but rather an issue with team dynamics.

Now that you’re aware that your flareon hosts a level of hostility towards your scyther, your next step is to determine why. This could be for any number of reasons. Does your flareon act this way towards all bug-types or just your scyther? Was your flareon raised by someone else who had a scyther, or did you catch him in an area with a high population of wild scyther? Did the amount of time you spend with your flareon change when you got your scyther, or did you change its living arrangements? (Did it used to be an outdoor flareon until you had to make room for your scyther, or vice-versa?) Do his teammates treat him differently now that your scyther is part of the team? The answer to any of these questions could be the reason behind your flareon’s behavior—or it could be something completely different. Keep an eye on your flareon for a few days to see if you can spot any clues that point to any specific reason.

It’s only after you can discern what the issue actually is that you can work towards resolving the matter. Without knowing why your flareon is reacting this way, it’s difficult to recommend a particular course of action because each situation requires something completely different. For example, if your flareon’s behavior stems from a past trauma, that requires a specific form of therapy (perhaps even exposure therapy), but if he’s simply jealous, then it may be as simple as reassuring him you haven’t replaced him. It could even be that your scyther accidentally provoked your flareon, at which point it would require mediation between the two. Or the reason behind your flareon’s behavior could, again, be none of these things, which would mean you would need a completely different strategy.

The point is, try to figure out why your flareon is acting this way through observing him first, and then you’ll be able to work towards a peaceful solution.