Whispy Woods' acquired ship piece could probably not be his fault. When they were flying through the air the oars could have landed in his branches. He attacks Kirby on sight because he doesn't like him; and when he is beaten and does a Chain Reaction Destruction it knocks the piece out of his branches.
The Plasma ability's merged with the Spark ability in this game. This isn't much, unless you realized via a Genius Bonus that Electricity's made up of plasma. Thus, Plasma ability merged with Spark the same way Burning merged with Fire and Freeze merged with Ice.
It's already circulated that the first letter of each world's name spells out the word "CROWNED." But there's another little layer to it. At first, even if you notice it after the first five worlds, then you'd think it's just foreshadowing the prominent crown atop Landia's head. Then, as the level moves onto Egg Engines and Dangerous Dinner, you realize that with that pattern in mind, it's not spelling simply the object, but a word used to signify someone already has it. And with an all-star hero like Kirby leading the way, the crown was already as good as Magolor's.
Take a look at Magolor's name. And then Lor Starcutter. Whether it was intentional or not, both have the word "Lor" in them. This could mean that he and the ship were destined to meet, and possibly that he had good intentions in the first place to collect the crown. But the crown itself had different ideas...
During the fight with The Lor Starcutter, it fires stars, launches oars, releases a whirlwind, and attacks you with boomerangs. What does it use to do these things? Its emblem, oars, mast, and wings, respectively. The same ones you had to collect. Yeah, that's right, by collecting all those parts, you essentially weaponized the Lor Starcuttter.
Look closely at Magolor Soul, particularly his center. With his mouth exposed and without his trademark robes, he looks less like Magolor's normal form and more like a demon- (or worse, Zero-) possessed Kirby. Also keep in mind that despite the name, Magolor Soul is a manifestation of the Master Crown, not him. If, say, Kirby had put it on instead, then he could have turned into that abomination, if not something even worse.
Notice how Magolor doesn't even put on the crown. It just floats onto his head. The Crown is no doubt sentient. Alive. And evil too. What if it influenced the alien even before the crowning?
There's speculation that the Master Crown itself is either a part of or made from Dark Matter. Which could mean that even Landia wasn't in control of their actions. Their eyes are green, then red when they wear the crown. And as soon as it's off, they're blue. I don't think that's a coincidence we should ignore...
Also, look at the state of Halcandra. There's also some speculation that Landia turned it into what it is now (lava, dying nature), if it wasn't that way already.