にせよEven if, Even though, No matter, Whether… or

にせよ, and にしろ are two phrases that are often translated as 'even if (A)', or 'no matter if (A)'. This structure is a combination of に, and either of the imperative forms of する; せよ, or しろ. せよ tends to be more common in written material, while しろ is more common in speech. Despite the English translations, this particular use of the imperative form of する translates more accurately to 'so it's (A), who cares!', as the speaker is just strongly stating that the actual condition of (A) is unimportant in relation to what they actually want to say.

にせよ and にしろ can appear following verbs, い-Adjectives, な-Adjectives or nouns in any of their standard forms.

As this structure is fairly direct, in most cases it will be used as a way to emphasize that regardless of what the case is for (A), (B) is still true, or is the more important matter to consider.