So, Isis, the one who's been talking to him in his head (and by extension, to his harem) is a loli? If that's the case, awesome.
Isis, the AI Support System, shown her "first body" appearance in ch.28 (the girls vs Alicia who went insane-ish) but only to the girls as she manifested herself physically to help save them (in particular Marianne/Maria), and not to the mc, yet, as she said to them "by the rules, conditions and procedures" set up by the wretched "rotten" creator goddess who gave "Isis" to mc/Touya
iirc Touya was the one who allowed Isis to help with the girls and him via the "telepathy" thing in the first place during the war/invasion of the demon side that time, and since then that time, she now freely communicates with Touya and the other girls (who're attached to him both in love and as "family" via slave and whatnot by his ridiculous skills)