That's if they don't manage to get loose. If they do, then they come out somewhat weaker, and the person they were inside, now KNOWS what they did, and who they are.
They're the ones who think that whatever host they're inside, what happens to the host doesn't happen to them too. But they're also the ones who tend to die with their hosts, and lose their original bodies forever.
That was what happened to my brother.
The hosts who are friendly and known to the skinwalker, or who even invite the takeover, the skinwalker can get into their memories and impersonate them, and they've got their own problems. The person who got taken over may or may not be able to tell what's happening. Usually not. But the skinwalker usually does nothing to ask their consent for anything crazy or risky they do.
Because they're not fighting, they don't change or age inside, and their hosts tend to become healthier (if they don't counteract that by living too wild and risky.) And a skinwalker who's sick can often recover by finding a willing healthy host to hide in for a while. It even cures some incurable things. And of course they can enter another person without leaving their current host.
These ones are the most dangerous though... because if they enter a second host with the body of their first host, and there's any resistance at all, even a little bit of discomfort, their host will become a skinwalker after a month or so of being inside other people, because they have to work to stay inside.
This is also what happened to my brother, and what turned him into a skinwalker.
Normally, like vamps, new skinwalkers want to share this new thing with all their friends, and that's not OK, because it's almost certain that they won't get enough training ... because the ever-so-slight forcing thing becomes addictive for the "parent" skinwalker and it takes training and willpower to stop.