A Fate Worse Than Death blanks the target's text box until the end of the phase, but Tsukune's interrupt triggers when the phase ends so is it still the conflict phase or the start of the fate phase when that would go off?

Edit: Nevermind found the answer on fiveringsdb. Tsukune would trigger before A Fate would expire.

Specifically, an Interrupt must happen before the event it refers to, and thus by definition, the effect must occur before the combat phase ends.