Anti Genetic-Hero Darkspore units, the sole purpose of the Operatives was to disable and quietly kill Heroes on the battlefield, before anybody realized they were there.
Among the first creatures to become Darkspore Agents, gravitic confiners employ their talents towards ruthless results. As medium-range levitators, they navigate any battlefield easily, seizing and trapping their quarry inside glowing energy spheres, where they remain immobilized and helpless. If wounded in battle, confiners teleport randomly to escape further damage. Despite the damage they can inflict, they lack resilience.
These Agents temporarily retreated after half of their Damage was lost, meaning that you still need to keep an eye out. They usually reappeared quickly.
Anything that disrupted its Channel should be used when fighting them. Push, pull, suppress, stun, even switching next to them would break their concentration. Hit hard, fast, and with extreme prejudice.
This was purely speculation, but another possible strategy would be to spawn pets (i.e., as Char, Sage, Zrin, or Savage) and have them attack the Confiner. Again, this was speculation and never tested.
It was possible to defeat them alone with Blitz or Vex using Ride the Lightning or Chrono Blink, by teleporting to them, retreating while they were frozen, repeat, until they died of the damage. This was more effective with Vex, though caution was advised, as the Confiner was a Quantum enemy.