The Big Sister is a fast, agile, and incredibly dangerous adversary. She appears after you've rescued or harvested all Little Sisters in a given area. Her attacks include a powerful melee lunge, a ranged Plasmid attack (often Telekinesis or Incinerate!), and the ability to summon Splicers. Her primary weakness is her relatively low health compared to a Big Daddy, but her speed makes her hard to hit. Use Winter Blast to freeze her, then unleash your most powerful weapons (Shotgun, Launcher, Spear Gun) for critical damage. Electro Bolt can stun her, but she recovers quickly. Set up traps (Trap Rivets, Cyclone Trap) in areas where she's likely to pursue you. Always be on the move and utilize cover. Rewards include a significant amount of ADAM and unique Tonics upon research completion.
