[Question] Pokemon rom hacking - Enforcing overworld poison effect.

[DragonWolf2b]

Hi,

I'm sorry if this question was already asked somewhere else or if I put this is the wrong forum.

I'm making a new small Emerald rom hack and I wanted to add an overworld effect as if the world itselfs "glitches". Now I looked into a bit and I think the overworld poison effect could give me this kind of desired effect.
I tried looking into if it was possible to enforce this effect with a script and as far as I could find nobody has really a good source for it.
I have found out you could give a pokemon a status effect, but that was not exactly the effect I was looking for (I could possible use that as an alternative though).

So I wondered if anyone knows if its possible to write a script that would enforce the overwold poison effect? Ideally without the sound of poison or actually decreasing the pokemons health in the party, but if that is a necessary side effect, then I could live with that.
If you know of another way I could generate an overworld effect that I could use to make it feel like the world "glitches", feel free to post something here as well.

thanks for your help in advance.