どうせAnyhow, At any rate, In any case, I have no doubt that, Probably

どうせ expresses resignation or pessimism about an inevitable outcome, often with a negative tone, as in どうせ失敗するから (It’s bound to fail anyway). In contrast, 何といっても emphasizes something’s outstanding or most important quality, as in 何といっても彼が一番だ (No matter what you say, he’s the best). The former carries a defeatist tone, while the latter asserts something positively.

何しろ introduces a reason or emphasis, often justifying a statement, as in 何しろ忙しいので行けません (In any case, I can’t go because I’m busy). どうせ conveys resignation or futility, as in どうせ無理だ (It’s hopeless anyway). Both can be translated as ‘in any case’, but 何しろ is explanatory, while どうせ carries a negative, defeatist tone.

These two forms both relate in a sense to an unchangeable fact, but differ greatly in usage. ～というのは事実だ literally states that something is a fact, e.g. 何もできないのは事実だ ('It's a fact we can't do anything'). どうせ expresses resignation or futility with a more emotional nuance, e.g. どうせ無理だよ ('It's hopeless anyway').