Anti Genetic-Hero Darkspore units, the sole purpose of the Operatives is to disable and quietly kill Heroes on the battlefield, before anybody can realize they are 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 will temporarily retreat after half of their Damage is lost, meaning that you still need to keep an eye out. They usually reappear quickly.
Any thing that can disrupt its Channel should be used when fighting them. Push, pull, suppress, stun, even switching next to them will break their concentration. Hit hard, fast, and with extreme prejudice.
This is purely speculation, but another possible stategy would be to spawn pets (i.e., as Char, Sage, Zrin, or Savage) and have them attack the Confiner. Again, this is speculation and has not been tested.
It is possible to defeat them alone with Blitz or Vex using Ride the Lightning or Chrono Blink, by teleporting to them, retreating while they're frozen, repeat, until they die of the damage. This is more effective with Vex, though be careful, as the confiner is a Quantum enemy.