Atlas Fontaine, the the final Boss, has three different styles of attacks: Flame Plasmid, Ice Plasmid, and Electric Plasmid Form. An easy way to defeat him in the first part is to use your Ice Plasmid and freeze him. Then, switch to your Telekinesis Plasmid. Grab an explosive tank, and throw it at him. Also, if desired, just use your telekinesis. He is very predictable if you are far away from him. Wait for him to throw a fire ball at you, then move out of the way. He will continue to run past you. Use this chance to fire the machine gun, which does the most damage to him. Once he goes back to his chamber to gain his life back, change to the Flame Plasmid, and get ready for some bots. Once he starts his routine of fire and run, shoot him with the Flame Plasmid as many times as possible. Continue to use the machine gun while he is aflame. He will now go back to his chamber one last time. He will now have electrical powers. Keep your Flame Plasmid ready. Shoot him with the Flame Plasmid, and he will run for the water. Once he jumps in the water and comes back out, hit him with it again. Be aware that there are Splicers all over as well; set them ablaze to get some extra life. There are many different ways to defeat him, but this is an easier way.

An easy way to defeat Atlas Fontaine is to make sure that you have the fully upgraded shotgun and the Decoy ability. After you drain his Adam, drop a decoy and while Atlas is attacking it, use the shot gun. After you have used all four rounds immediately cast Decoy again, reload your shotgun, then begin shooting him again. Repeat this until you have to drain his Adam. Once again, reload your shotgun and Plasmids before you drain his Adam. Then, start over using Decoy and the shotgun. Use health packs as needed and ignore any Splicers in the area, as they will be paying attention to your Decoy just like Atlas.

1: In Peach Wilkins' hideout (Neptune's Bounty), bottom floor. As soon as you come downstairs, it is directly in front of you.

2: On the way to Farmer's Market in Arcadia, the station is located to the left after you go up the first stairs coming from Tree Farm.

3: Go to Winery's basement in Farmer's Market. There is a flooded area with one of them attached to the wall. It is in front of you when you come down the stairs; just keep going forward.

4: In Fort Frolic, from the Atrium bottom floor, go towards the bathrooms. Then, move right and follow the path until you see some small stairs to your right leading up to a door. Go inside, then go down into the basement. The basement is filled with cigars and other stuff. The upgrade station is on the wall.

5: Go to Poseidon Plaza in Fort Frolic. Go to the other end of the bottom floor (the opposite end of where you enter). Go into Sinclair Spirits (the room that has a corpse on a sort of "altar"). In the basement of this store is the station.

6: In Hephaestus Core Room, go down to the bottom floor, and run around (literary). Eventually you will see it attached to the wall.

7: In Hephaestus, Kyburz's office. It is attached to the left wall (back turned to the entrance) in the rear of the room.

8: At the bottom floor of the Mercury Suites area, on the back of the center pillar.

9: In Sander Cohen's secret room, in the Olympus Heights' Mercury Suites area.

10: Go to Atlas' Headquarters in Apollo Square (Fontaine's Home For The Poor area). It is located on the fourth floor. Go down the stairs in the room and look to the right. The station will be in front of you.

11: When you enter Point Prometheus and chase Fontaine, eventually you will end up in a little square, and Fontaine will go behind a locked Museum door. At the opposite end of this square (from where you came) is a dead Big Daddy. Next to it is the upgrade.

12: In the Voice changing labs in Point Prometheus, one of the labs has it.

Save the game before fighting a Big Daddy or other difficult enemies. If you do not like the results (used too much health, wasted too much ammunition, etc.), you can simply reload your saved game and try again until you are satisfied.

After becoming a Big Daddy, create a new saved game. At this point, you will be close to the end of the game. If you missed something, you can go to the Bathysphere and explore Rapture again; you are also a Big Daddy now so the Splicers will not harm you, security cameras will not set off alarms, etc.