I killed two in Tamoe Highlands, now terror zone shifted to Marsh, do i just continue to kill mobs and hope for a third, fourth and fifth Herald?

I need to stay in the same game and same act, or ?

Go anywhere that is a tz. Drop some shards if you have time and don’t want to wait for zone changes

But i must stay in the same game to get the Third herald, right ?

You can’t leave the game because the terror progress stacks within the same game, not across different games. That’s why shards are useful. You don’t have to sit around waiting 30 minutes for the next zone. I usually pop a shard and clear that act, then rotate to whatever zones become terrorized every 30 minutes if they’re in other acts, just cycling back and forth between areas.

tyvm

is it always 2% chance for a herald to spawn or does the percentage get higher once you have spawned the first herald?

If anything heralds spawn less frequently after 5-10 spawns. That’s been my experience but I haven’t played a ton only level 93

You had any luck with getting the sunder charm?