Must you KO a Hero when a Villain's Spectrum effect says KO one of your Heroes?

Question

Accepted Answer

No. The KO is optional: you can reveal a Spectrum card to avoid it, and you may choose to KO a Hero if you want to remove a weaker card. Only a KO with no "you may" choice is unavoidable.

Legendary: A Marvel Deck Building Game

Must you KO a Hero when a Villain's Spectrum effect says KO one of your Heroes?