- Narcissus 2 begins the fight by jumping out of the mirror and landing in the middle of the room, sending out five mirror pieces and four mirror waves that make their way to the four corners of the room, each one spawning a Mirror Pylon.
- These Pylons can be destroyed by Narcissus 2's various attacks, as well as the player's explosions (bombs, Ipecac, ect). When destroyed, the Pylons send out five mirror pieces that travel to the opposite corner the pylon was in, and fit themselves into the wall they hit. If the player is hit by these mirror pieces while they are in the air or in a wall, the mirror piece will disappear.
- Following Sin Update, these Pylons now heal Narc 2 whenever he is damaged and usually have to each be destroyed to progress the fight. They also take a few seconds to break when struck with the right force, giving the player short time to dodge the mirror shards.
- Narcissus spits a bomb at the player, sending out six mirror tears when it explodes. If the bomb hits a pylon, or explodes near one, the pylon will break.
- The explosion from the bomb can break mirror pieces that are in walls
- Narcissus is more likely to perform this attack if the player is in between Narcissus and a pylon.
- Narcissus jumps in the air and slams back down, sending out short mirror waves in all directions and knocking the player back against a wall. If the player is knocked back into a pylon, the pylon will break.
- If the player lines up to the left or right of Narcissus, Narcissus will lunge and punch the player, sending out three mirror pieces behind him then smashing against a wall. If Narcissus hits any pylons while he is lunging, the pylon will break.
- At 60%, 40%, and 20% health, Narcissus will clear all mirror pieces in walls, detonate all remaining pylons (sending out new mirror pieces), and jump into the mirror. A mirror chest will be in the mirror, and Narcissus will smash it open, giving him a variety of different items that have different effects based on what the item is. After the items have done their effects, he will jump back out of the mirror, sending out four mirror waves and spawning four more pylons.
- Tiny Planet: A tiny planet spawns and begins following the player. Five tears orbit the tiny planet.
- Guppy's Hairball: Guppy's Hairball spawns and loosely follows the player. Upon dying, it will split into two smaller hairballs.
- Bobby Bomb: Spawns a few bombs that home in on the player.
- Caffeine Pill: Makes Narcissus smaller and faster until he gets the next set of items.
- Magneto: Sucks the player to Narcissus.
- Samson's Chains: Slows the player if he walks out of the chain's length, pulling the ball along. The ball can be destroyed by the player.
- Charm of the Vampire: Heals Narcissus three times if the player is hit by any of his attacks.
- Shade: Spawns a Shade that follows the player at a delay. The shade will disappear if it hits the player or if Narcissus is hurt into his next phase.
- Rubber Cement: When Narcissus comes back out of the mirror, the mirror waves that are sent out will bounce off the walls a few time before settling in their corners and creating pylons.
- Spoon Bender: When Narcissus comes back out of the mirror, the mirror waves that are sent out will home in on the player before settling in their corners and creating pylons.
- Robo-Baby 2.0: Spawns two Robo-Babies from outside the room that fire lasers at the player.
- Dead Bird: Spawns eight birds from outside the room that directly follow the player.
- Following the Sin Update, Narcissus 2 has a new attack. He roars and summons lasers from any active pylons in the room. These lasers first target any mirror shards on the walls and then shoot from shard to shard a few times before stopping.
- The more lasers are activated, the slower the attack speed is.
- Narcissus will always drop either Mirror Shard or Mirror Fragment; it will only drop the latter if the former has been collected.
- Narcissus II is made out of mirrors, and is a representation of a reflection of Isaac.
- Narcissus II makes use of Passive Items extensively, morphed into versions which are harmful to Isaac.