I heard somewhere that having Nasty Plot + Stored Power on a Togekiss is possible through chain breeding. But I did some research and I didn't know how to do it. Please help ?
You can't.
Nasty Plot: Honchkrow / Plusle / Minun Stored Power: Clefairy / Clefable / Xatu / Natu
No Pokemon can know both that can breed with it. Source