Rising Event

[Iscah]

So it stayed active with the npc available the whole 3 hours?

Every time I checked (fairly often), yes. I don't know if there was a cutoff point where some people might be asked to wait because the instance was full, but I went in and out a few times on different characters.

There isn't a start and end of the instance, in practical terms - it's a cycle of five FATEs, after which the NPC "in charge of the commemorative exercises" will declare it's finished, but will start again soon. You don't need to leave the instance after that, just wait, and then the scenario starts again. You might enter the instance at any point in the cycle.