R.O.B., Rayquaza, and Waluigi watched in curiosity as both Popo and Nana were giant sized, knocking parts of the Halberd apart as the aircraft was slowly heading down towards the enormous, red colored sea likely soaked with the blood of Dreamland's citizens... but that's not what you wanted to read.
"I don't know why anyone would want to be big," Rayquaza explained (for you) as he began spinning around at the speed of sound, making some of the fighters that were having a Smash battle on the stage dizzy as they were circling around the Halberd.
"Because it makes them feel superior and gives them a feeling that they're valued," ROB stated as he was looking at a couple of metallic bits that he thought of adding to himself to enhance his fighting performance. "I am of the mindset that anyone can do what they want, regardless of size. I mean, look at Olimar, he's an amazing fighter, yet he's supposedly smaller than any of us..."
"Peh! Size, who cares?" Waluigi snapped as he was briefly summoned to do his job as an assist trophy, stomping the Smashers on the ground as he smacked them into the air with his tennis racket, popping back up in front of ROB and Rayquaza as he flexed. "Look at me! I'm athletic and healthy, yet no one is willing to let me do some damage!"
ROB and Rayquaza glanced at each other as all of them fell, with the Halberd officially sinking into the sea as Popo and Nana laughed evilly, giving each other a high five as they began to dance on the sinking ship.
"Calm down, folks! Now is not the time for fear!" Popo exclaimed to the trio that were fleeing the ship slowly sinking away, noticing that ROB and Waluigi were riding away on Rayquaza's back. "...That comes later!"
"Ooh I like where this is going!" Nana spoke up as she felt a warm most sensation in her pants, blushing with an embarrassed smile. "And so does my body, because is it just me or urine trouble!"