I've added Meta Knight to my Sm4sh mains, and Ravioko came up with “The Three Kings” as a name for them, since his are called The Four Horsemen. It makes sense 'cause purple is the color of royalty and I use the purple palettes (in MK's case, the default). I tried to keep the scaling somewhat canonically accurate, but with Greninja and Yoshi being so much bigger than Meta Knight it was nearly impossible to do.

In my own headcanon all the Yoshis other than the green one are referred to by their color, hence the Yoshi being called Violet. I guess she's the queen of the group...? idk

Yoshi © Nintendo
Greninja © Gamefreak
Meta Knight © HAL