This movie is lightly based on the classic work translated as "Investiture of the Gods", with the heroes canonized as Immortals at the end. Without this background knowledge the title definitely does not make sense.
shareThey are officially appointed as gods once the war is won like torasrogers says. But their powers are pretty much the same as before. So they are super powered humans or demons. Some of their powers are from learning skills and some from weapons / special items.
Chinese gods can be supreme beings like western gods but also just super powered humans who are drafted into the heavenly court that is mirrored on Imperial Chinese rule.