All demons have 5 bodyguards. Players have to defeat all of the bodyguards before they can fight with the bosses. There are three rounds in each boss fight (with the exception of the Interlude fights). Each round can last a maximum of 99 seconds.
- Main article: Lynx (SF2)
Lynx is the very first demon encountered in Shadow Fight 2. Lynx is the leader of a group of assassins known as "The Order". When he meets the player, he dismisses the player as a pathetic fighter, instead sending Shin to take care of the player. Lynx has five bodyguards who, once defeated, clear the way for the player to battle Lynx.
Lynx's weapons are his claws - which have a moderate range, high damage and outclass most of the weapons in the first province. Lynx is also the first enemy to use ranged weapons. His special ability is that he can throw down a smoke bomb and become invisible. When Lynx is defeated, he hands over the Blue Seal. Beating him will allow the player to buy ranged weapons in the shop. If the player defeats Lynx in Eclipse mode, they will get his claws as reward.During the fights with Lynx and his bodyguards, the track "Black Warrior" plays.
- Main article: Hermit
Hermit is the second demon encountered in Shadow Fight 2. He has five disciples - which takes the role of bodyguard. All of them have names based on martial art styles. Hermit is famous for his mysterious power, which is revealed to be Magic.
Hermit has destroyed all other academies in the town, so he can build his own school. It is revealed that Hermit's disciples resent him and only learn from him in an attempt to discover his secret and use it for their own benefits.
Dragon, one of Hermit's disciple, reveals that there is a competition, full of aspiring warriors that are trying to get a place at Hermit's academy. The winner will get to know what is Hermit's secret power.
Hermit wields a pair of one-handed swords as weapon, and is the first enemy to use magic. He changes his ranged weapon to a new one each round the player defeats him. Hermit can use his magic quite often because of the fast recharge of his magic. First, he uses Lightning Arrow, then switches to Water Ball after the player defeat him twice. Hermit's special ability is that he can enter a transcendent state that allows him to summon lightning strikes at will; however, Hermit is unable to move while casting this ability, so Shadow can attack him at will. Defeating Hermit, he will reward Shadow with the Green Seal and his secret power, Magic. If the player defeats Hermit once more in Eclipse mode, they will get his weapon as reward.During the fights with Hermit and his bodyguards, the track "Old Sensei" plays.
- Main article: Butcher (SF2)
Butcher is the third demon encountered in Shadow Fight 2. As with Lynx and Hermit, he has five bodyguards. His first bodyguard is Bird, who attempts to ambush the three protagonists (Shadow, Sensei and May). She leads them to a secluded part of town saying that it will take their breath away, once and for all. Upon escorting them to her destination, she attacks, but Shadow manages to defeat her. Bird's defeat brings forth the rest of Butcher's Gang, directing the protagonists to Butcher himself.
Butcher is a bandit who raises children from a young age, training them to be violent and aggressive. Butcher was introduced by name in Act II to the protagonist by Hermit, who says that Butcher has been harassing Hermit for some time now because he seeks for Hermit's magic.
Butcher wields a pair of meat cleavers, which cause bleeding effects on the player when they get hit. His special ability is that he can stomp the ground, which causes a small earthquake; If Shadow is caught on the ground when he lands, he will lose a portion of his health as well as fall. Defeating him will reward players with the Red Seal. If defeated once more during eclipse, player will get his weapon as reward.During the fights with Butcher and his bodyguards, the track "Sparring" plays.
- Main article: Wasp (SF2)
Wasp is the fourth demon encountered in Shadow Fight 2. She is the daughter of The Pirate King. With her father missing, Wasp became the new Pirate King. As with the other demons, she has five bodyguards who have their names themed on the sea. However, the first 3 "bodyguards" are members of "New Blood", a rebel group comprised of the pirate crews that doesn't trust Wasp. The last 2 "bodyguards" are Wasp's loyal mens.
During the fights with Wasp and her bodyguards, the track "Ship Battle" plays.
Wasp wields a green naginata. Her special ability is that she can jump off the edges of the battlefield and swoop across the screen, damaging the player; However, the attack can be dodged by rolling or a well-timed duck. After defeated, Wasp reveal that she indeed killed the Pirate King, after being manipulated by Widow. The reward for beating her is the Purple Seal. If defeated once more in eclipse, player will receive her weapon as reward.
- Main article: Widow
Widow is the fifth demon encountered in Shadow Fight 2. As with the other demons, she has five bodyguards named after animals particularly of cold regions, which serves to hint at the metaphor of her cold-hardheartedness and indifference towards her admirers, though she does seem to hint some genuine feelings for Shadow, as he was unaffected by her charm. Her "bodyguards" are people who were mesmerized by her magic and beauty, competing for her attention.
During the fights with Widow and her bodyguards, the track "Shadow Lady" plays.
Widow wields a pair of fans with a leeching effect. Her special ability is that she can teleport behind Shadow and backstab him, doing a noticeable amount of damage. This can be avoided by doing a very well-timed roll, a backwards kick as soon as she teleports, or simply intercepting her before she finished the teleport. Widow hands over the Orange Seal after she is defeated. If defeated once more in eclipse, player will get her weapon as reward.
- Main article: Shogun
Shogun was once a servant of the Prince, a man of royal birth. Seeing the incompetence of said Prince, and how his nation was falling to ruin because of this man, Shogun masterminded the assassination of the Prince, without the awareness of his mens, and seized power for himself. While the nation was certainly stronger and more powerful than when previously ruled by the Prince, Shogun's reign showed to be tyrannical and somewhat despotic, as hinted by Shogun's bodyguards.
During the fight with Shogun, his bodyguards, and General's mercenaries, the track "Burning Town" plays.
Shogun wields a pair of a katana and a wakizashi blade - the pair of blades is called Daisho. His special ability is that he can call his bodyguards, who will come from either side of the screen at random intervals, one at a time, and attempt to strike Shadow once before "flying" upwards. The summoned bodyguards can't be attacked. Their attacks can't be blocked, but can be avoided. Defeating him will reward the player with the last seal, Jade Seal, as well as unlocks Gates of Shadows. If the player defeats him once more during eclipse, player will get his weapon as reward.
- Main article: Titan
Titan wields a huge, two-handed sword called The Desolator. There is a handle attached on its side to aid in it's usage, since the weapon is so heavy.
Underworld bosses are the Eternals, they are powerful beings that has lived for thousands of years. Their domain is the Underworld. They awakened after the Gates of Shadows opened, aiming to destroys the world. A specific amount of players are needed to challenge underworld bosses. Their shield must be destroyed in a specific time (that is different for each boss). After that, players can challenge them. If they lose, they can repeat the fight until they won. Every fight can last a maximum of 45 seconds.
- Main article: Volcano
Volcano is the first Eternal encountered in the multiplayer act, Underworld, of Shadow Fight 2. He has hardened magma as his body and fiery flame as his hair. Volcano is one of the four bosses of the first floor. He has the ability to control fire. Volcano has a shield of 1700 points which has to be destroyed in 5 minutes and 20 seconds before the players can challenge him.
- Main article: Megalith
Megalith is the second Eternal encountered in the multiplayer act, Underworld. He is a stone-crystal humanoid being. His dungeon is a mine full of different gems. He has the ability to move earth to cause earthquake, he have moved even continents. Megalith has a shield of 5600 points which has to be destroyed in 10 minutes and 40 seconds before the players can challenge him.
- Main article: Fungus
Fungus is the third Eternal encountered in the multiplayer act, Underworld. He is a living giant mushroom and has power to control mushrooms. He has a shield of 11100 points which has to be destroyed in 12 minutes and 40 seconds before the players can challenge him.
- Main article: Vortex
Vortex is the last Eternal encountered in the first floor. He is a fish-human hybrid, with his humanoid traits being more dominant. He has the ability to summons a huge flood. Vortex has a shield of 19000 points which has to be destroyed in 12 minutes and 40 seconds before the players can challenge him. Player need to get Dan 3 before fight him.
- Main article: Fatum
Fatum is the first Eternal encountered on the second Tier of the Underworld. She has the appearance of an old woman with pale skin and yellow eyes. She wears black hood and robe. Fatum has the ability to see people's fate. She has a shield of 21000 points, which has to be destroyed before the player can challenge her. Player must reach Dan 4 to fight her.
- Main article: Arkhos
Arkhos is the second Eternal encountered on the Tier 2 of the Underworld. He is a rat-human hybrid, with his humanoid traits being more dominant. He also wears a tattered robe. Arkhos is the leader of rats. He also has gathered follower which he fed with lies. Arkhos has a shield of 24000 points, which has to be destroyed within 15 minutes before players can challenge him. Players must reach Dan 5 to fight him.
- Main article: Hoaxen
Hoaxen is the third and last Eternal encountered on Tier 2 of the Underworld. He is a two-headed humanoid creature, with tentacles on his back. He also has humans' faces covering his abdoment and one of his shoulder. He has the ability to drive peoples mad with illusions. Hoaxen has a shield of 28000 points, which has to be destroyed within 14 minutes and 30 seconds before players can challenge him. Players must reach Dan 6 to fight him.
??? is the unknown boss yet to be released. It is placed in the Tier 3 of the Underworld. Players must reach Dan 8 to fight it. It is the final boss of underworld.
- No boss can be shocked.