Title - Idk something having to do with outside the Solar System The expansion should be centered around the cabal launching a full scale invasion of the solar system with us killing all of their command in TTK and the Cabal getting a last minute signal out to The Cabal Empire. It could start of with them coming in and just destroying the reef (since the queens dead) and thus removing the vestian outpost as a social space. Then it could go on to them trying wanting to take complete control over Mars and thus attempt to destroy the black garden. Once this fails the Cabal resort to just trying to blow up Mars but they don't and only half succeed leaving mars with a giant gash and split into chunks. After wards would be Earth (we'll skip venus so we can save that for a Vex DLC) Since the Cabal didn't learn their lesson on Mars and still don't know not to try a Full Scale attack they make landing on Earth in the (European or Any Other) dead zone. Where from there launch an attack on the City which means we actually have to defend it (!) and fight in the streets and along the walls (Thank you Titans). After our victory we assess the losses and then find out that the Cabal are going to Crash the Moon into the Earth (raid) and that the Emperor himself is overseeing operation there Bungie Pls i just handed you the plot for Destiny 2 EDIT: Plus add in Space Combat it would fit EDIT 2: To fit this can take place about a year or 2 after TTK so everything can look nice and new and different like the Tower and Also to replace the Vestian Outpost we made Phobos into a base of our own.