I don't entirely know all of what dommy mommy lady lucifer is trying to imply here, but she's got her eyes on Namba, at least.
Should be fun. Anyway, time to mention a few things. 'Practitioner' is kinda used like a 'rank', maybe an initiate or acolyte. Um, Sumire continues to be hard to write for since there are double meanings to a lot of what she says. I'm pretty sure most of her lines are somehow tangentially implying she wants Shina to have more self-compassion. So I changed her lines around a little to reflect that. I get the feeling that En's line of saying "I'll need to do my best too." might make more sense as a camaraderie type statement like "We'll just have to do our best, together." but I kept it literal, since I don't want to imply its a romantic statement. Romantic/ romcom statements seem to be Shina's thing. Shina usually has a romantically oriented/ stereotypical female lead statement every few chapters... but En doesn't say things like that.
Finally I'll mention that Shina actually says "I'll have to tell Shina that Mikage is really strong." but that confused me for quite a while when I was reading it originally... so I think "my little brother" as a statement makes it a bit more clear Shina is speaking in character with the intent to be overheard by Mikage.