Seeing how Misericorde's memories inform the power he's taking from her was a nice touch. Since it is her heart, as you established, and his intentions are far different from her own, it's nice to see the pushback from her... as well as contextualizing her curiosity in him earlier through his memories.
I'm very curious about Hlifa and how she'll fit into things. After all, even if they're somewhat open, Ignis is still waiting on the other side, and it's not quite clear if Hlifa is even actually alive. Keep it going, though, you've got some good intrigue building and character development brewing.