when eve said she'd save Silvy she meant it cuz when Rosie leaves and removes her imprint on silvy just like the previous lifetime, silvy's life was in danger so fl imprints on silvy to save his life or else he would've died. Oh and at that time the imprint of eve on ml was broken cuz he had become the king of homunclus and continuing the imprint would've put eve's life in danger and when silvy tries to serve eve for the night time duty she refuses him telling he doesn't have to do it, Michael was jealous of silvy becoming eve's personal knight but he was more grateful to her for saving his friend's life