[subject] + 虽 + [predicate],但 / 却 + [predicate]
话虽如此,[clause]
虽 is the one-character written form of 虽然, "although". It goes after the subject, in front of a short predicate, and the next clause turns with 但 or 却.
虽然 can go before or after the subject. 虽 stays after it.
虽 suits a short predicate – one adjective, or a verb with its object. A long clause after it reads unevenly, and 虽然 is the better choice there.
话虽如此 – "the words are so, although" – grants what was just said and turns against it: "that may be true, but".
虽 survives in several set phrases. 麻雀虽小,五脏俱全 – "the sparrow is small, but it has all its organs" – says something small is complete. In 虽败犹荣, 犹 means 仍然: lost, yet still with honour.