He's not in the Outlander's mind. He's visiting/knocking on the door. The only time someone mentions he's there, is when V is actively talking to you. At every other point multiple npcs are telling you that they sense nothing else (including brainscans by droids). Lana and Heskel both only "see" a glimpse of V, and in both cases, only during that exact moment V's whispering away with his seductive power offerings.
At a guess, he's incorporeal and bounding about the galaxy. That whole "son of a gun, that twerp blindsided me" laugh when you shanked him is pretty much the whole "well, the game's afoot!" phase of being... bored. So, he's up to challenging himself, kinda like doing a leveling grind without gear for us. This is a stage of "well, nothing better to do, so, let's see..." kind of stage.
Ziost changed something, removed some sort of challenge V didn't think he would be able to get around. He was also in the end-game building up Zakuul for an attack on the rest of the galaxy... only for one of the kids to snag it. So, he's playing a game with "well, I could just smash away, but let's see how this plays out."
In other words, far too overpowered. He's going to be something nasty at some level... I figure something like Sephiroth's One Winged Angel form is at play in a raid in the near future. Not certain that would tie off the story, but... he's just playing at being a smoke monster at the moment.