Vivian's Trial starts at this reset and it is an event that will repeat a few times. In the event you can get maps from boomers, use the maps to summon Berseker Zombies, defeat Berserker Zombies to get Vivian's Fragments to star her up, and you would also get a chance to get compases that can trigger an unearthed treasure event with some more hero fragment rewards. The event is usually pretty straightforward. But you can use the maps to summon and defeat Berserker Zombies after event, so if you have collected enough Vivian fragments for the event goal, you might want to collect more maps and save them to use them after the event, when you can no longer get those maps. It gives you a chance to earn more fragments than normal, and make your Vivian hero stronger. It is an important step in the right direction.