Requires:

"Gravity"
{
  "or": [
    "Ice",
    "ScrewAttack",
    {
      "enemyKill": {
        "enemies": [
          [
            "Evir"
          ],
          [
            "Evir"
          ]
        ],
        "explicitWeapons": [
          "Plasma",
          "Super",
          "PowerBombPeriphery"
        ]
      }
    }
  ]
}

Dev note: Other weapons take too long to kill the enemy.