The Fire Knight can be the final boss on the 2nd or 4th level of the dungeon, or a smaller boss on the 5th level of the dungeon
The Fire Knight has two attacks
The Fire Knight extends an arm and a ring of 10 (ish) pillars of fire expand outward in a circle. They are very slow moving projectiles but take up a lot of space making them hard to dodge.
The Fire Knight charges, similarly to many of the other bosses, except as it charges, it moves considerably farther than many others, and has a much larger hitbox while charging. As it charges it's arm's extend outwards and spin like a helicopter towards the player. A player hit by the arms takes 1/2 heart of damage.
The Fire Knight has two forms of movement like many of the other bosses, a slower walking speed and a much faster charge.