让步状语从句部分倒装.
引导让步状语从句的连词主要有以下这些：though,although,as; even if,even though; whether...or...; no matter+疑问词,疑问词-ever.
however good it was 这里However即疑问词-ever,被倒装的部分是表语good.
其它例句：
However (=No matter how) expensive it may be,I’ll take it.无论它有多贵,我也要买下它.
Don’t let them in,whoever(=no matter who) they are.不管他们是谁,别让他们进来.