Frank Fontaine is using the fake identity of Irish man Atlas to manipulate the protagonist who he also has the ability to mind control using the sentence "would you kindly?" due to the protagonist's childhood brainwashing. his goal is to take over the ruined underwater city of Rapture so he can take the world's supply of ADAM. which is a highly addictive substance that gives you both powerful super powers and brain damage. he is highly manipulative, cunning, dangerous, greedy, power hungry.