Flier Emblem is my go-to team for the first 6 rounds of Tempest. I use Ninian as dancing support, Palla and S!Camilla with Reposition and Goad, and Hinoka with Pivot and Hone. With all the movement options I can often do the first few rounds taking no damage. Even when the game throws a Takumi at me (guaranteeing one of my fliers will die), I can still normally make it to round 6 or 7 with two fliers and a dancer.
At round 7 I switch them out for my bonus hero team (Tharja, S!Lucina, Hector, Olivia). Usually an easy victory, excepting the times when I'm presented with 4 greens, which gets a little dicey.