Twin Dragons Achievement
Defeat the Twins simultaneously.
Not entirely story related, but something that will likely happen on any one of your four playthroughs. It doesn't have to be in the exact same strike, just within a few seconds of each other. When one Twin is down, the other will revive him. This allows for their health to even out as well as land some attacks. The Twins seem to be more susceptible to interactive objects than other bosses so knock a goon down, pick him up, and swing him around. *This can be achieved on any difficulty*