それにしてもNevertheless, Even so

Both introduce contradiction. それにしても can mean even so or nevertheless, and can also be used to change topics, as in それにしても暑いね (Even so, it’s hot, isn’t it?). それなのに marks direct contrast, closer to and yet, as in 一生懸命勉強した。それなのに落ちた (I studied hard, and yet I failed).

Both can mean nevertheless. しかしながら is formal and used only for explicit contrasts, as in 雨だった。しかしながら試合は行われた (It rained. Nevertheless, the match was held). それにしても is common in everyday speech and can also serve to shift topics.

それでも and それにしても both express contrast. それでも adds a contradictory point neutrally. それにしても accepts the previous idea, but adds what the speaker really thinks, often a more critical or stronger opinion, e.g., 暑いね。それにしてもよく歩くね ('It's hot. Still, you sure walk a lot.').

Both express contrast, but with different nuance. ところが introduces an unexpected result, e.g. 試合に勝つと思った。ところが負けた ('I thought we'd win the game. But we lost.') それにしても acknowledges the situation but adds an emotional reaction or further judgment, e.g. 仕方がない。それにしても悔しい ('It can't be helped. Even so, it's frustrating.')