This is a parody of Hallelujah by Leonard Cohen.

I heard there was a tennis game
Which brought a purple lad to fame.
However, there is just one oddity.
'Cos never did he once again
appear in a Nintendo game.
This purple person's name is Waluigi.
Wah-llelujah, wah-llelujah,
Wah-llelujah, Waluigi.

But then Smash Ultimate came around.
Nintendo fans were very loud,
About the fact that everyone was there.
This wasn't true, and Waluigi
wanted some of the action too.
You know you want, just add Waluigi!
Wah-llelujah, wah-llelujah,
Wah-llelujah, Waluigi.

Hats off to you, my purple friend.
I hope you make it round the bend
Of popularity 'cos I adore you.
I think you're great, this isn't bait
I fight for you for Smash rights too,
C'mon, Nintendo just add Waluigi!!!
Wah-llelujah, wah-llelujah'
Wah-llelujah, Waluigi.