In this rule St. Ignatius talks about what happens when I am drifting in my relationship with God. What happens? As can happen in any relationship, there is a lack of delicacy, negligence of details, little interest. So what does the devil do? Well, he is, of course, ecstatic that I am not growing in holiness. So he says, "you're doing great," while the Holy Spirit says, "wake up!"
The devil wants to be a catalyst in aiding our growing further from the Lord. Pretty obvious, right? So what does he do? St. Ignatius says in the rule that "the enemy is ordinarily accustomed to propose apparent pleasures to them, leading them to imagine sensual delights and pleasures in order to hold them more and make them grow in their vices and sins." He is trying to attract us to that which leads us away from God. This could be something as simple as something I like which prevents me from getting to Sunday Mass.
In this stage of the game, says St. Ignatius, the "good spirit uses a contrary method, stinging and biting their consciences through their rational power of moral judgment." We have all experienced that, right? It's so easy, too, to try reasoning my way out of it. But something has to change and so the Holy Spirit employs this methodology.
But this all changes when I change direction.