Angela managed to bring Sera back from the dead at the end of Queen Of Hel's first arc, and they lived happily together in NYC for a while, the book got cancelled and then Bendis happened. He used Angela in his GOTG book for months without one single mention of Sera, and when he finally decided to address the situation, in the penultimate issue of his run, he basically wrote Sera off of Angela's story; claimed she just disappeared from the apartment she shared with Angela and gave no explanation to what happened to her. That happened in March of 2017. Ever since, the story's been unresolved. Just recently, an editor confirmed via Twitter there's still no solid plans for Sera.