"As Awilix, pull a knocked up enemy using Gravity Surge"
You're ult gives you a boost, and allows you to pull an enemy that is knocked up in the air in front of you. You can see a blue icon on the enemy you can pull when the ult is ready.
You can knock up someone yourself using you're third spell ; or have a friend like Bacchus, Hercules, Sobek (there is a lot of knock ups in game)...
Finally you can also use you're ult against an enemy that have a jump (Neith, Bacchus, Hou Yi...)
Pretty easy achivement...