From Destinypedia, the Destiny wiki
The Captain is a class of Fallen. They are a known rank of Fallen, carrying themselves with an air of superiority and nobility. They have been shown to wield most Fallen weapons, and are almost always enshrouded within an absorption shield. They have the ability to teleport short distances.
Captains are the fiercest rank of Fallen on the battlefield. They lead their crew with their superior combat prowess. The weapon they wield will effect their behavior. Captains will usually be armed with a Shrapnel Launcher, in which case they will push towards Guardians very aggressively while firing canisters of shrapnel at their target, because the weapon is especially effective at close range. If armed with a Shock Rifle, they tend to keep their distance and pick the player off from there by sending homing Arc projectiles downrange. A Captain can also be seen wielding a pair of Shock Blades. They will fearlessly charge into the fray to cut their targets to bits. However, a Captain is likely at his most deadly when armed with a Scorch Cannon, which he uses to devastating effect, being able to instantly kill Guardians at any distance, and are also very aggressive when closing in on their targets. For improved durability and mobility, their armor has an embedded Arc shield as well as teleportation tech. Although they will break off an engagement when their shield is broken down, they are otherwise fearless and will charge into battle at any chance they see fit, even if the odds are against them.
In Destiny 2, Captains fight differently, making use of hit-and-run teleportation tactics to overwhelm their enemies. Captains will attempt to quickly shoot you, then dash away with a teleport, repeating the process. An attempt to break this engagement with heavy-fire is recommended. They also sport a slightly thinner, more streamlined look.
List of appearances