Hey everybody,
Dark Phoenix's card says "at the start of each combat phase, KO all resources in play". Does that apply just to the person who controls Dark Phoenix or is it a blanket effect for all players?

"KO all resources in play."

When in doubt, read the card literally. Cards always do what they say. More importantly, they don't do anything they don't say they do.

in other words: it's a blanket effect for all players;)