The Ol' One-Two

The Ol' One-Two is an Achievement/Trophy in Clash in the Clouds. The Achievement is worth 15 Gamer Score and the Trophy is bronze.

Requirements
The player will have to kill an enemy with each of the 8 official Vigor combination in the game.

Strategy

 * Keep track of the Vigor combinations that you have performed, as it might be hard to remember which you have performed and which you haven't, when trying to perform the last ones.
 * Make sure that the enemy is killed and not merely hurt, as such, it is best to focus on one enemy.
 * Be especially cautiousness when performing Murder of Crows and Possession combinations.
 * Human enemies are objectively the easiest to kill.
 * Try to lower an enemy's health before using a Vigor combination on it.
 * It is recommended to upgrade each Vigor to the fullest, so that the Vigors do as much damage as possible (can be done at a Veni! Vidi! Vigor!).
 * Instead of going through wave after wave (which becomes harder overtime), the player can start up a map, Raven's Dome is recommended, perform the Vigor combination, die and start over.

Behind the Scenes

 * The Achievement/Trophy icon depicts a crow (from the Murder of Crows logo) under a crown.
 * The name of the Achievement/Trophy is a callback to BioShock, where Atlas tells Jack to use the one-two punch against a Splicer. The one-two punch is when one hits an enemy with Electro Bolt and then with the Wrench.