Form of mist vs relentless reaper

If i have player Form od mist to end the combat, and then my opponent played relentless reaper for new round of combat.

Can i use abiliy to continue action when this combat ends?

Form od mist

Strike: combat ends. If this vampire is acting and needs stealth after this strike resolves, he or she can burn 1 blood after combat ends to continue the action at +1 stealth as if unblocked (even if stealth is not yet needed). A vampire can play only one Form of Mist at superior each action.

No, you can't.
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Any effect that starts a new combat after the combat that was ended by (or continues the combat that was ended by) a "combat ends and the action continues as if unblocked" will nullify the "continue action" part. This includes Psyche (superior), Fast Reaction, Hidden Lurker, and Telepathic Tracking. [LSJ 19980109]
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