This appeared in the dialog of a recent Tatort episode:
Wenn alle Beteiligten nur wissen, was sie wissen dürfen, wenn alle nur denken, was sie denken sollen, dann wird kein Ermittler und sei er noch so gut, ausreichend Beweise finden, die für eine Anklage reichen.
sei er noch so gut
appears to be translatable as something like, "no matter how good he may be" or, more word-for-word literally, "be he yet so good". But I do not understand several aspects of this construction.
- This is not indirect speech, nor is it imperative, so why use subjunctive I?
- The word order seems wrong with the verb in first position when the statement is neither a question nor an imperative.
- The word-for-word English interpretation seems to somewhat miss the intended English meaning. Is this a fixed-phrase or is there a more general class of statements to which this belongs?