If you wait long enough, a Waver will arrive. After it turns around to go back to the right, damage boost off of it, then follow it. Continue to hit it to get i-frames to avoid taking damage from any spikes. The amount of Waver hits can be reduced by running ahead on the spikes and taking damage from a second Waver instead of following the first Waver.

Requires:

{
  "notable": "Damage Boost (Left to Right)"
}
"canHorizontalDamageBoost"
{
  "enemyDamage": {
    "enemy": "Waver",
    "type": "contact",
    "hits": 2
  }
}
{
  "or": [
    {
      "and": [
        "canUseIFrames",
        "canTrickyJump"
      ]
    },
    {
      "enemyDamage": {
        "enemy": "Waver",
        "type": "contact",
        "hits": 3
      }
    }
  ]
}