~にせよ/~にしろ (regardless of)

The concessive pattern ~にせよ (or ~にしろ), meaning 'regardless of X / even if X / granted that X.' Concedes one point before making a contrasting or qualifying statement, or dismisses the specific condition as irrelevant to the main point. 何にせよ ('whatever the case may be'), 理由が何にせよ ('whatever the reason'). Similar to ~にしても.