No, you can’t invite anyone, at least for the time being.
One does wonder if it’ll happen during act 3… Sawano did mention healing properties…
But it could also just be side content that will be added in act 2 once the game enters the beta phase.
i know who i want to join me there at least :)
could also be cool to have Quarinah do some more water-centered dreams, since you know... dreams... would love to have a very wide variety, though with all i want to do with/to her alone, i don't think you can keep the size under 2 GB, nor finish it before i somehow land a girl in the real world :)