He's not grieving for Jess anymore but he's grieving for the loss of his humanity now. I don't know if Jess should leave. I think he is responsible because he's the one who made Yohan a vampire and therefore should guide and help him, but also, I think Jess should leave because I don't think Yohan still loves him anymore.
Eclise's doesn't know that his obsession for his Master Penelope has led him to replacing her with another Master, and that is Yvonne, by following her orders and not Penelope's LMAO