Kinetic Grasp
Cooldown: 12 seconds
Absorb projectiles in front of you and convert them into extra health.
Accretion
Cooldown: 10 seconds
Gather a mass of debris and throw it at an enemy to knock them down.
Gravitic Flux (Ultimate)
Needs to be charged
Manipulate gravity to lift enemies into the air and slam them back down.
In case the video won't load here's the external link.
A Guide for the Hero Sigma from Overwatch
The narrator talks about the hero generally then summarizies it's abilities and how you can use the effectively in the most precise but shortest way. In the background there are clips from the game, possibly it's the narrator's gameplay. He talks about against which heroes can and can't be this specific hero be used.