Adverb (fukushi)
in any case; regardless; either way; after all; no matter what; anyway
indicates inevitability of outcome, resignation or scorn
どうせやるなら上手にやれ。If you do it at all, do it well. since it makes no difference anyway (you might as well ...); since it won't change the outcome; if you are doing it regardless
followed by a conditional, or as ～...だから