[Funny Trope] "This is MY moment!!" Wait no it isn't.

Lapis Lazuli (Steven Universe): Lapis spends most of the series on the sideline for various reasons, most of them avoiding the conflict. In the episode Reunited, she returns to put up a good fight against the Diamonds, and after five seasons FINALLY declare herself a Crystal Gem. A bit later, she says "What else have you got? I've only just BEGUN to fight!" before almost comedically getting annihilated instantly and once again written out of the plot for the next four episodes before returning in the fifth, where she also gets knocked out and written out of the climax.

Poison Ivy (Batman and Harley Quinn): This movie is just weird, but basically Floronic Man is the threat with Ivy on his side most of the movie. Ultimately she turns on him for Harley's sake, and manages to BARELY fight back against him in a rather badass moment of tearing apart one of his grass appendages, declaring "the plant world, belongs to ME!" for emphasis as the heroic music swells.

Then Floronic Man just fuckin DECKS her in the face and thats the end of her contribution.