Super Smash Brothers Ultimate - A layered bit of wordplay

I get it, because Galeem's Japanese name is Kira, which is also the name of the main antagonist of Death Note, who is actually Light Yagami, and light is the pun that Galeem's name is based on, but also Light uses the Death Note to kill all criminals, including people who engage in tax fraud, such as Yoshi, which is the first part of the user of Killer Queen's name, Yoshikage Kira. Good one XD.

Actually not light, kirakira (キラキラ), which means "shine, twinkle" and the Kira in Kira Yoshikage (吉良, spelled with kanji, not kana) actually literally means "good luck" when you separate the kanji which is wordplay with the Killer in in Killer Queen while kira in Galeem's and Light's case is just phonetic for killer (キラ).

It's important to remember that Japanese doesn't work the same way as English. Also while I haven't read or watched Death Note, I'm pretty sure that Light is the protagonist, main villain yes but not main antagonist, that would probably be L.