しかもMoreover, Furthermore

それに and しかも both add information, but しかも is stronger. それに is neutral: it adds a point that logically follows. しかも emphasizes what comes next, like 'what's more' or 'on top of that', e.g. 安い。それに美味しい。しかも体にいい ('It's cheap. And tasty. And what's more, it's good for your body.').

その上 and しかも can both appear at the beginning of a sentence to introduce additional information. They are often interchangeable, but しかも is somewhat more colloquial and can imply that the added information is unexpected. その上 is more neutral and formal, with no such implication.

Both add extra information. しかも is neutral, adding notable facts, as in 彼は優秀だ。しかも親切だ (He’s talented, and moreover, kind). おまけに can add positive or negative on top of that nuance, as in 雨だった。おまけに風も強かった (It was raining, and on top of that, the wind was strong).

Both add information, but differ in nuance. しかも emphasizes reinforcement or surprising addition, as in この料理はおいしい。しかも安い (This dish is delicious. And what’s more, it’s cheap). 更に is more formal, indicating progression or escalation, as in 明日は更に寒くなるでしょう (Tomorrow it will get even colder).

しかも and なお② both add additional information, but differ in nuance. しかも often strengthens the previous statement with surprising or emphatic detail, as in 彼は優秀だ。しかも努力家だ (He is talented, and what’s more, hardworking). なお② is more neutral and formal, used to supply further facts without emphasis, as in 今回の件について、なお調査中です (Regarding this matter, we are still investigating further).

Both express addition like the English 'moreover', but differ in usage. しかも starts a sentence to add information that emphasizes the previous point, e.g. '彼は優秀だ。しかも努力家だ' ('He's talented. Moreover, he's hardworking'). 又〜も, because of も, must be used with another noun that also applies and adds to the previous statement, e.g. '姉はピアノが弾ける。また、歌も歌える' ('My older sister can play piano. She can also sing songs').