Is the meaning of the Almighty’s saying, “Indeed, the plot of Satan has ever been weak,” (Satan) Iblis, or the jinn of devils? And does “has ever been” imply continuity, or that his weakness has ceased?

This verse is part of Surah An-Nisa, and it comes in the context of discussing jihad. The "Shaytan" mentioned therein could refer to Iblis or the jinn (devils) in general. "Kāna" (was/has been) here implies perpetuity and continuity, meaning that the devil's plot has been weak and continues to be weak since his existence.