In game encounter that is really rare Example: You stumble upon a village in the wilds that are under attack and you go in and clear the threat to the village. Encounter specials: There is a high ranked leader in the encounter that you kill and gives a rare drop / loot. And you also receive a title "Savior of - the name of the town"
If it will be mostly single player game, I see no point in titles as every player can save the very same village at different times. So it wont highlight you at any point.
The encounter is really rare and can only happen once for each town or city. And if you do save it with some of your friends the title apply to all participants. So the idea is that it is not possible to attain the title in the offline part of the game.
There is no proper explanation provided on what will be mutliplayer part of the game and what will be the offline one. So we don't know what exactly will it even work.
Savior? Nah, I don't like it, sounds like if you earn respect from certain NPCs based on how you treat them or your karma level they will treat you like this anyway, I personally wouldn't want such a title to even exist. Some cool titles I would recommend though would be; seer, magi, sage, hierophant, bane.