When an enemy comes in contact with the halo, a beam of light starts to form above them. If they stay in the halo for about a second, a beam of light will strike down on them, dealing 3.5 damage and creating 4 more beams that shoot out in all cardinal directions.
The initial beam of light does 3.5 damage per tick (up to 15 times) and the others deal 1.75 damage per tick (up to 15 times).
If an enemy is standing in the center of all the light beams, they will take a total of 152.5 damage.
Each time Isaac takes damage, the halo will grow in size, up to a maximum of 10 times. The halo size will reset after leaving the floor.