I was actually just discussing this with a friend last few days! I have a version with my Twins AU, but putting that aside, I still think it will be strained and complicated. No matter what, you can't write off the fact Maleficia allowed Lilia to be banished twice over now. The first time you can say it was the grief of losing her only child, but then it happened again after Lilia was the reason Malleus was born. She then allowed their kingdoms history to be changed to the point the timelines didn't add up just to erase the fact of what Lilia did. Part of what made Malleus so furious was because of what Lilia went through, but also because his own grandmother allowed that to happen on top of lying to Malleus is whole life while doing it. It will be difficult to rebuild that trust again, but I do believe they will be able to. I do believe Maleficia does love Malleus like crazy. The fact she later allowed Lilia to come see Malleus when he did shows she was aware of Lilia's importance to Malleys. But she let her fears of losing her last connection to her daughter take hold for too long, and that hurt Malleus in the long run being sheltered the way he was and he wasn't even allowed to know why beyond that he lost his parents during the war.