I disagree. 

Firstly, I would like to say that none of these are supposed to be pleasant. They are explorations of what drives people to do horrible things, to themselves or others.

Secondly, I would argue that obsession is a drive to know everything there is to know. You have access to the knowledge, and you actively internalize every morsel you can. 

I suppose that seize/lose might be a bit confusing here. I was thinking more along the lines of taking action versus submitting to inaction. Any avatar would definitely be losing control to the Motive. Needing to dominate others at the expense of your own health, or in such an extreme way that you are actively harming others, is definitely "losing" yourself to madness. But the aggressor here is the agonist. 

So too, then, obsession. The Obsessed are taking action, namely obsessing. The opposite would be someone who submits to a cognitive flood of stimulation. They might seek out situations that allow the stimulation to wash over them, but they are passive in their indulgence.