This is based on opinion. Please don't list it on a work's trope example list.
She was already both a
non-ironic and sad clown (with just a dash of
Stepford Smiler to boot) to begin with, but one unmasking later, she's pretty much the latter two now.
Chapter Five: Welcome to Clown Town
- Mustard discovering the identity of Echo after a prolonged fight: her sister Maggie, who was assumed to be dead.