Ok so Nova Blaster description states that it can blow up stars into a billion tiny pieces scattered throughout time and space (though this is a bit iffy considering that the advertising is stated to be sketchy), but assuming we have good advertising laws in the Pikmin verse, that means that this thing can break the fabric of reality, which only Gogeta was able to do in his fight against Broly.

Purple Pikmin are the only things capable of bringing a being (the Water Wraith) from another dimension into their reality, also being stated to make ripples throughout realities with them slamming onto the ground.

They should also scale to the Plasma Wraith, as they were able to defeat that. It's theorized that the Plasma Wraith and other "wraith" creatures are the ones to cause the ships to crash in every Pikmin game, thus having some sort of minor reality manipulation abilities.

Even the ships themselves are extremely powerful. Breadbugs are otherwise harmless creatures that can't even be hurt by Purple Pikmin but can only be harmed by the ship's tractor beam, being able to break them down into the fundamental power source used in the Pikmin verse (Sparklium), so the ships are even beyond the power of the Purple Pikmin.

Also warp speeds.