yeah we would probably need new strats at this point to save another second, because here you have to hope that the first/second grenade blows up enough enemies on the balcony to quickly trigger the boss checkpoint, then line up the shotgun melee attack perfectly both in terms of distance and time. Finally you have to use 0 EMP grenades and just hope that the attacks miss you until you "break" the crystal viper, and your shotgun needs to hit the boss well enough that you can finish them off in just 6 shotgun shots.