You can typically unlock the Prism class by completing Scenario 58 or Scenario 59 .

If you mean the itself (a summoner-type enemy from certain late-game scenarios):

Here is a breakdown of the Hive, ranging from their lore to their mechanics.

Uses the Repair Drone mode and Armored Tank for high survivability and self-healing while acting as a front-liner.

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It is explicitly categorized as a high-complexity (5/5) class. Some players find it frustrating due to the heavy administrative work of managing multiple tokens and tokens' movement.