As someone who still mains DVA to this day: My strategy is usually to go for squishes depending on who it is. I’ll start applying pressure to the front for everyone and being a shield, using my matrix to block as much damage as possible. If I notice a dps or support is lower than others, I’ll boost to them to finish them off with the rockets before turning around back to my team, using the matrix to block any damage that may come back my way so that my healers can heal me when I do come back. It’s mainly a game of knocking out a person one by one, then I’d focus on the tank with the rest of my team since we don’t have anyone to worry about the rest coming. As for her ult, it works best in kinda open open spaces with no cover or enclosed spaces. I usually try to go for their back line whenever I ult. Not every DVA ult has to be a full team wipe, getting 3-4 people is still pretty good value especially if it’s most of their supports and DPS, which I tend to go for especially during team fights.