When Quinn had disappeared from the group's sight, they looked up and they could see him rushing towards the portal. They wanted to reach out to stop him, and Edvard and Hikel even somewhat attempted to do so by jumping up.
However, they were unable to fly, or walk in the air like Quinn was able to, and even if they could he was already too far gone for them.
He had reached the portal, and the strange red mist energy that was coming out of it, was attaching itself onto him. There was a bit of resistance at first, almost as if the mist was trying to push him away.
It felt strange, as if a part of his body was being rejected by this other world. When he felt this, he let out a bit of his aura, and in doing so, something strange had happened. Suddenly, rather than his body being rejected, it was being more accepted and it felt like he was being pulled by whatever was on the other side.