The first major story choice you'll face in Dragon Age: The Veilguard is whether to save Minrathous or Treviso. Both cities are facing simultaneous dragon attacks—bad luck there, Rook—and it's up to you to figure out which one you'll rush to the defense of.
This decision takes place immediately after you get back from recruiting Davrin the Grey Warden, so be aware you're going to be ambushed by this choice before you can get back to The Lighthouse to debrief with your team. Neve and Lucanis will come running to meet you in The Crossroads, explaining that they've gotten word that both their hometowns are being attacked by blighted dragons controlled by those elven gods you've been learning about.
Like many things in a Dragon Age game, there's no one right answer to whether you should save Minrathous or Treviso. It all comes down to how you want to tell your story—from your choice of faction to which companion you want to align yourself with. Both choices lead you to a brief fight with a dragon.
As you'll know by now, Minrathous is Neve's home and Treviso is home for Lucanis—minus that recent stint in the Ossuary you just saved him from. Obviously they both make the case that you should help them protect their own city. Neve will point out that if a dragon creates chaos in Minrathous, the Ventatori cult of blood mages will take the opportunity to stage a coup and take over the city. Lucanis argues that Treviso basically has no defenses apart from The Crows and that the merchant town will be decimated by civilian casualties if blight from the dragons gets into the water supply.
With all of those concerns onboarded, it's up to you to decide which city to save. No matter what you choose, Neve and Lucanis will each defend their own city. So if you choose Treviso, you'll pick one party member to join you and Lucanis to save it but Neve will not be available. The opposite will be true for saving Minrathous. This decision does come up again down the line in act 2 in which the city you save will turn up to have your back at a key moment.
If you choose to save Treviso, Minrathous will face some serious damage from the dragon. Neve's allies in the Shadow Dragons will be injured and the Venatori presence in the city will increase. Neve will also stay in the city to help her friends for a while, meaning you won't have access to her as a party member until she returns after you've finished recruiting the final members of your crew.
If you save Treviso, Neve will be "hardened" by the experience. Your relationship progress will be slower with her and you'll notice she's a bit colder and more reserved when she first returns to The Lighthouse. Neve's combat abilities will also change. She'll get increased damage buffs at certain passive skill nodes but she'll no longer be able to use the Replenish healing skill at all or certain support upgrades to other abilities.
If you choose to head to Dock Town to help Neve fight off the dragon, the sequence is very similar to that in Treviso; you make your way through the city, fighting some Venatori cultists along the way, before you arrive to find Neve and the Shadow Dragons. You'll drive off the dragon and save the day… kind of.
As you were fighting in Minrathous, the city of Treviso fared less well. In particular, Lucanis takes the fall of Treviso very hard and it's been confirmed that it will prevent you from pursuing his romance. Here's everything that will happen:
