Quick answer — Saori Katou voices Esal in Erin, Karen Lo in Jormungand, Harpie in Ronja, the Robber's Daughter.
Saori Katou voices Esal (Erin), Karen Lo (Jormungand), Harpie (Ronja, the Robber's Daughter).
Esal is voiced in Japanese by Saori Katou.