You can earn this achievement by using Athena's
(or 2). The ability is a cone shaped taunt that pulls enemies toward Athena.
In order to earn the achievement you must simply get three or more enemies in a single taunt. Ultimate this will not be too hard in any of the game modes but can be expedited in arena by waiting for a good grouping or by going to the buff camps at the beginning of each match and hitting them while they wait for the buff.