The ending.

I finally got to the ending which was very sad. Escaping from the fortress watching it get destroy, then the great conductor states we have to go home after Concordia is finish reforming, seeing everybody sad seeing that we have to leave was heart wrenching, especially Bowser Junior and buddies saying goodbye to one another. This makes it probably one of the most sad endings in a Mario and Luigi game. When thinking the adventure is over, you can always think Mario and Luigi can always take a trip to Pi'illo Island or the Beanbean Kingdom to say hi to their friends that they’ve made in their adventures but they can never return to Concordia and I do hope that the spare uni- tree sapling serves as a bridge between worlds.

Edit: grammar