Srlgnas, could you address an alternate story where Rimuru acquires an Ultimate Skill from the Chaos Series (Virtue + Sin), after integrating Gluttony and Great Sage into a single Skill? (Due to the fusion of two Unique Skills of such caliber, it is expected that an Ultimate Skill will be born).
This could help Rimuru on several occasions, especially in his battle against Hinata Sakaguchi and Charybdis. And during his ascension to True Demon Lord, Rimuru could name this Skill and give birth to Manas: Ciel, but, with a completely unpredictable style of thought and psychology, due to the origin of Chaos.
I don't fully remember times when this idea could be used, after all, it's been a long time since I watched or viewed Tensei Shitara Slime Datta Ken content (mainly because I haven't read the Novel, and I'm just following the Manga at the moment), but I think if anyone could find ways to take advantage of this idea, it could be you. By the way, I don't think you'd like to address it, but it would be interesting to see a love triangle between Ciel x Chloe x Rimuru, in this case, everyone treating each other as equals in the relationship and loving each other romantically, I don't really like harems where there is a certain difference in attention and etc between the couples...