i don't think there's any coherent or compelling explanation to this notion of being "in the grip" of Se.
some of the behaviors could be attributed to being tempted to find pleasure/well-being in the world, but they would probably relate as much or more to e5-->e7 temptations as a way of improving feelings of satiation and to work against the diminishing emotional energies of the e5 as the excessive head-type mental energy burns itself out under extreme stress, the person loses almost all sense of actual PRESENCE, and instead starts to feel kind of like a town that was devastated by a hurricane.
similarly, i think the sense of being antagonistic often has to do with a trust issue and feeling ultimately powerless. once your emotional system starts to flatline, and your lack of mental energy combines with your relatively low sense of presence and decisive instinctive body type active energy (which is more of a base-line condition of e5), and once you're left with continuing problems that you cannot accept and lose belief/faith/contentedness (heart type energy), you're left with diminishing motivational resources, and it's difficult to continue to think positively and maintain emotional openness and listening. both w4 and w6 are rather low in well-being in general, according to some enneagrammatic theories (and w6 do seem to be more fixated on feeling controlled, whereas w4 do seem more fixated on alienation and being fundamentally alone). as a result, your acceptance ability goes down, which is to say, your ability to stay positive and let go of unlikable or challenging things, and so you see others as threatening and enemies who you hate for having power when you do not, and you are generally more reactive and hostile because the warmth has all gone out.
so as for being in the grip, i think it's more about the emotional emptiness of an intense anxiety burnout than about Se by itself. i think, however, injs vs itps as e5s might have somewhat different responses because their cognitive realities would be significantly different in construction, and Fe inferior might try to use others to manage their own needs without offering any consideration whatsoever.
i think infj e4s, e1s, and e9s also might have different responses, just as instinctual stackings would influence how the person looked to find a sense of well-being after they've become more distorted by completely burning out one of their go-to pathways due to inflexibility, extreme stress, and just not maintaining their best operational controls through some turbulent periods that are generally both internally and externally conflicting.
it seems to me that the cognitive functions are more cognitive and affective intelligences/abilities, but the actual process of stress management is given not only based on the ability to manage outcomes and relationships but also on the internal psychodynamics of how those are interpreted to shape one's motivation, mood-priming, assumptions, and behavioral response patterns.