Attack Phantoon with one or two Missile shots, then fire a charged Plasma shot when it comes back around; use X-Ray repeatedly while the charged Plasma shot is in contact with Phantoon, to wait out Phantoon's i-frames, making it possible to kill in one cycle. Note that using a charged Plasma shot initially (without first using Missiles) would cause Phantoon to immediately close its eye and not take any more damage during that cycle.

Requires:

"Charge"
"Plasma"
{
  "or": [
    {
      "ammo": {
        "type": "Missile",
        "count": 1
      }
    },
    {
      "and": [
        {
          "resourceCapacity": [
            {
              "type": "Missile",
              "count": 1
            }
          ]
        },
        {
          "or": [
            "canTrickyJump",
            {
              "enemyDamage": {
                "enemy": "Phantoon",
                "type": "flame",
                "hits": 1
              }
            }
          ]
        }
      ]
    }
  ]
}
"canXRayWaitForIFrames"
{
  "or": [
    "canTrickyDodgeEnemies",
    {
      "and": [
        "canDodgeWhileShooting",
        {
          "enemyDamage": {
            "enemy": "Phantoon",
            "type": "flame",
            "hits": 2
          }
        },
        {
          "enemyDamage": {
            "enemy": "Phantoon",
            "type": "contact",
            "hits": 2
          }
        }
      ]
    },
    {
      "and": [
        "canTrickyJump",
        {
          "enemyDamage": {
            "enemy": "Phantoon",
            "type": "flame",
            "hits": 1
          }
        },
        {
          "enemyDamage": {
            "enemy": "Phantoon",
            "type": "contact",
            "hits": 1
          }
        }
      ]
    }
  ]
}