TBL savior achievements seems to consist of mission challenger achievements rather than the usual setup of partisan,mercenary and hero achievements. This seems unintended as the the savior achievements have the same description as all the other expansions.
Not a bug, it was done intentionally. Does it match the other expansions ... nope, but that doesnt make it a bug. It was discussed at length, during beta .... 18 months ago.
Really? Well, then the description is still wrong, as it directly states: . or is that intended too? What was the reason for making it different? just curious.
Pretty sure Savior is more to direct you to the achievements to gain Hero Fortitude and Vitatity AAs, although it's certainly not completely consistent since being introduced. It is clear that the description is a text bug for the TBL Savior achievements. So there's that.
It would probably be a disaster if they fixed it to match all the earlier expansions this late anyway, retroactively removing peoples achievements/hero-AA/augs... Fixing the description should be relatively trivial however. Not a big deal though.