WindmillOfFriendship
And as for the two sisters, now depowered and mortal, they'd thank Twilight and her friends for everything they've done for them. They'd fly off into the sunrise and look forward to their future endeavors,confident in Twilight's capabilities in bringing a new era of harmony to Equestria and the rest of the world. This would probably fit more in the series finale if the two sisters play a role in it.