First you need to store the reference returned by Instantiate:
GameObject child = Instantiate(groundTrailParticle, ds.wFx_.position, ds.wFx*.rotation) as GameObject;*_
Then set the parent by assigning to transform.parent (here I’m assuming you want ds.wFx to be the parent, change if that’s incorrect): child.transform.parent = ds.wFx*.transform;*
It seems like it was because I was trying to parent a ParticleEmitter.
It worked when I instantiated it as a ParticleEmitter then parent it. I’m not sure though lol, it could just been my incredible retard powers acting up again.
Thanks for help though. It helped.
ParticleEmitter ptc = Instantiate(groundTrailParticle, ds.wFx_.position, ds.wFx*.rotation) as ParticleEmitter;*_