Hi, in the portal room after the tp there is pz so you can't regenerate mana/hp while waiting for the team. If you decide you want to leave outside to get your mana regenerated, you are teleported to Thoris temple which does not make sense to be honest. At insigoma room there was no pz and you could summon a dummy target to train there. It was much better.
Another point are rewards - many people do not want to participate in the event because it's not worth it, i.e. rewards are not good enough.