Responses
Not sure bada seems not to be part of game from the beginning but Doha started to change all of a sudden may be system is changing Doha was actually a mystery character in game at the end who would be the real thing. Just my guess
If Doha was the type to die trying to help, why is he so easily taking out the murderers now? Is it because before becoming aware of the game he didn't quite know what to expect/what was he defending himself from and now he's got Bada who teaches him all kinds of useful stuff? As a former NPC maybe he's got some additional knowledge that combined with Bada's notes gives him the upper hand?