8 Video Game Villains That Helped You Beat Other Bosses
1. Atlas - Bioshock
Now let's face facts here, "helping" is a very loose term that you could use to describe the "assistance" offered by the one and only Frank Fontaine, as his idea of offering a helping hand is done so by plotting you like a puppet on a string, and here the string has been replaced with a knife in the back.
In short, Mr. Fontaine betrays the ever-loving heck out of you, and does so by hijacking Jack's brain through the use of his trigger phrase "would you kindly". When these words are uttered, Jack, and by extension the player, have no choice but to follow his orders to the letter, which all take you towards the other larger-than-life persona of Rapture, Andrew Ryan.
By following Franks's orders, you destabilize much of this underwater hellscape and capture the attention of Ryan who eventually relents to a rather disastrous peer review. However here lies the double twist, as it's Ryan himself that demands his own execution, meaning that a villain helped you beat another villain only to be beaten by the other villain themselves!
And technically for her experimentation and originally cruel persona, Brigid Tenenbaum is another villain that offers assistance, eventually removing the control phrase and giving you the ability to take down Atlas once and for all.
It's a backstabbers ball!