Not much is known about the Zenturi. They are not from this timeline, and are apparently made of matter that cannot interact with matter from this timeline, at least not without a currently unknown in-between. They are implied to have created the main transformation trinket of the series, Swarm 1, and then used it for unknown means. They are currently seeking to destroy it, as it apparently represents a threat to their current plans, whatever those are.
The Zenturi have displayed the ability to create pocket dimensions and fire beams of destructive energy. It is worth noting that their abilites share the same purple energy as Swarm 1's contructs and weapons.
Zenturi are dark purple beings with a humanoid shape, eight sharp fingers, no mouth, blank eyes, and some sort of purple gem in their forehead.
Is It Okay To Just Get Fired Up?, where a Zenturi tried to destroy Swarm 1 by killing Napoleon. It was eventually killed and faded away when Napoleon turned into Batdrill and managed to drill a hole through its torso.
Machina Ex Deus, where six Zenturi teamed up to kill Napoleon, and almost succeeded. All six were eventually destroyed by Napoleon after a brutal battle.