If you really want to role play as a mysterious character that is famous for dragonslaying, isn't it the best option to simply be considered nameless except for your alias itself? But that's just my point of view considering my thought-processes in heavy roleplaying.
Also one tip if you want to back up your alias with actual skills of dragonslaying, never ever let the dragon get out of the cave. In other words, never ever let it fly. Although that's only necessary if your DM took tons of notes from Tucker's Kobolds.