"Programmed to not buckle in a fight, BB units serving the First Order often finds themselves in the crossfire. BB-9E is such a battle-hardened veteran."
— Star Wars Battlefront II website
Similar to BB-8, BB-9E's main weapon is a shock prod that will stun enemies while dealing damage. Due to its low damage output, his weapon is best used on one-on-one engagements or on low-health targets. If with another ally, the stun will be most effective in keeping them immobilized for long enough for the ally to get the kill.
BB-9E is primarily a support hero with abilities that reward friendly players who stick close to him. His passive ability Bacta Support heals friendly units around him by a small amount. This may be improved with the Potent Bacta Star Card. Also like BB-8, BB-9E has the passive ability "Technical Support" that allows him to count as two units when capturing Command Posts, useful in modes such as Supremacy, Co-Op, Instant Action, and certain phases of Galactic Assault.
BB-9E can also emit a smoke screen that obscures the immediate vicinity around him, while at the same time revealing the position of enemies in short pulses. Lightsaber users in particular will have a hard time tracking BB-9E. However, there are certain ways to see through the smoke, like Lando Calrissian's blaster scope.
His Shock Spin ability knocks back opponents right next to him and overheats the blasters from enemies farther away from him and disables incoming projectiles. It is especially deadly if used on a ledge that has a large drop, as you will be knocked out of the map.
While Shock Spin disrupts blasters, Charge Up does the opposite, as it grants unlimited cooling to nearby allies' blasters for a short period. If there is a Captain Phasma nearby, she will gain the benefits of the ability as her blaster will become more accurate the longer she fires. It also decreases the cooldown time of friendly units' abilities.
On activation, BB-9E pushes and damages close by enemies with an electric pulse. Enemies further away will have their blaster overheated and grenades disrupted. BB-9E will damage close by enemies for the remainder of the active time.