The boss arena is a giant underground lake with an island in the middle, we walk across shallow water onto the island, in front of us were three monsters, I'm getting bad vibes from the one in the middle.

Race: Titan Abyssal Serpent Species: Reptile Monster

Level: 88

HP: 185000/185000

MP: 64000/64000

Status: In-Party

Endurance: 15600

Attack: 14500

Defense: 17800

Magic: 23400

Dexterity: 19600

Innate Skills:

Serpent Scales

Water-Breathing

Aquatic Movement

Skills:

Poison Fang (S)

Water Magic Mastery (-)

Poison Magic Mastery (-)

Physical Attack Resistance (S)

Magical Attack Resistance (S)

Elemental Resistance (S)

Titles:

Dungeon Boss

Race: Thunder Megalodon Species: Fish Monster

Level: 88

HP: 205000/205000

MP: 53000/53000

Status: In-Party

Endurance: 17300

Attack: 25800

Defense: 21000

Magic: 13600

Dexterity: 15800

Innate Skills:

Flight

Electric Absorption

Skills:

Body Strengthening (S)

Water Magic Mastery (-)

Electric Magic Mastery (-)

Physical Attack Resistance (S)

Magical Attack Resistance (S)

Elemental Resistance (S)

Titles:

Dungeon Boss

Race: Supreme Abyssal Hydra Species: Dragon

Level: 90

HP: 478000/478000

MP: 134000/134000

Status: In-Party

Endurance: 48600

Attack: 78400

Defense: 88400

Magic: 53000

Dexterity: 48000

Innate Skills: 

Dragon Scales

Dragon Breath

Body Regeneration

Parallel Will

Skills:

Claw Mastery (-)

Four-Attribute Magic Mastery (-)

Physical Attack Resistance (S)

Magical Attack Resistance (S)

Electric Immunity (-)

Mental Status Immunity (-)

Titles:

Dungeon Boss

Titan Abyssal Serpent

Danger Rank: A+

Thunder Megalodon

Danger Rank: A+

Supreme Abyssal Hydra

Danger Rank: S+

What the fuck!? What is an S+ monster doing here!? That thing can actually kill us, it's not as strong as Crya but it still far outstrips us, what is with that stat difference between peak A+ and a newly evolved S+, is there something special when evolving to S-rank? Also, they're in a party.

...

Why!? Now it's going to be far harder to kill these three, at least the two A-ranks are far more manageable only being about a little stronger than the Aquatic Killer Tarantula that can be found in the dungeon. Did no one come to clear out this dungeon in a long time so the monsters here have gone up in strength, I feel the dungeon would be ranked at least S as it currently is.

The entrance is already sealed off, well then, it looks like its do or die time.

(Lilith) "Rosa. This is going to be our hardest battle yet."

(Rosa) "nods Let's show them that our teamwork never loses."

The moment the battle started there is already magic flying everywhere, I'm currently fighting the Thunder Megalodon while Rosa distracts the other two with magic. I land on its head and hit it with repeated Dragon Fists, jump off its head and fall straight at it and use Death's Saw Blade creating a large cut on its neck. I land and it attempts to attack me with its tail, I take it head-on and grab it, I use Judo Throw to throw it directly at its party members, they crash into each other, the Hydra didn't move that much thanks to its far superior stats, I have to remember that its defense stat is actually than Crya's who is an Ancient Unique Monster, this Hydra is no slouch. While all of them were bunched together, Rosa attacked.

(Rosa) "True Combination Magic! S-Rank Spell Hell's Domain."

A small black orb shot out of her hand straight at her opponents and then expanded covering all of them. 

Hell's Domain is a spell that combines Abyss and Explosion, a High-rank Dark Magic and War-Class Magic, but with the fire element removed and the dark element bolstered.

After ten seconds three blue lasers shot out of the Hell's Domain and caused the spell to collapse, the Hydra broke the spell through firepower. 

Titan Abyssal Serpent

HP: 140000/185000

Thunder Megalodon

HP: 157000/205000

Status: Bleeding

Supreme Abyssal Hydra

HP: 450000/478000

Well, we're making some process. Right, when Hell's Domain was fully shattered, Rosa and I were surprised by a Dragon Breath and we're directly hit and went flying. I use my scythe to grip the ground and Rosa used teleportation to stop her momentum. 

Rosa

HP: 56000/215000

Lilith

HP: 113000/257000

 It did that much damage with one attack!? We can't take more than one hit from the Hydra or we're dead. Rosa casts healing magic bringing us both back to full.

(Lilith) "Rosa, if that Hydra lands a hit, heal immediately. We can't take more than one hit."

(Rosa) "Yes. True Combination Magic! S-Rank Spell True Titanic Fortress!"

After saying that we both start glowing with a silvery light. 

(Rosa) "This spell should reduce all damage we take by 80%, it will last 10 minutes."

Rosa has already used up about a third of her huge MP pool. 

(Lilith) "Ten minutes is more than enough time. smirks"

(Rosa) "True Combination Magic! S-Rank Spell War God's Blade!"

I start having a second layer of glow that is red.

(Rosa) "Your damage is increased by 250% and speed by 50% for five minutes. Go get them, Big Sis."

I rush at the bosses and create two scythes, and start launching energy blades at them, some landing and some not, I use Phantom Step creating clones of me all over the place, all moving as if they were alive, I teleport behind the megalodon and use a double scythe Death's Saw Blade and cut off its head.

Decapitation!

Thunder Megalodon 

HP: 0/205000

One down. The megalodon had the weakest scales, the other two bosses noticed and are going mad at losing their friend. I pick up the megalodon's magic stone and eat it. I rush at the onslaught of high-rank water magic, I use Phantom Step and disorient them, Rosa is using magic to create a bunch of explosions to both damage the bosses and create a smokescreen to hide me. I teleport behind the serpent I use both scythes to stab into its eyes. I take out my kodachi dump 30000MP into it and stab straight into its head and cut open its head, and go down its spine, and then Rosa uses Embrace the Dark on its exposed head finishing it off. There are serpent guts all over, it's super gross.

Brain Destroyed!

Titan Abyssal Serpent

HP: 0/185000

There goes the second all that remains is the real boss, and he is mad. I pick up the Serpent's magic stone and eat it. The Hydra is going berserk and is breathing water dragon breath all over we had no place to dodge and we're blasted back and from the corner of my vision, I see one of the heads smack Rosa down from midair.

(Lilith) "Rosa!"

Rosa

HP: 200/215000

Status: Unconscious

Rosa! I run forward where Rosa was and her humanoid form reverted back to her slime form and the pink symbol on her body was dim. I look at the hydra and the hydra roared at me. 

My mind is clouded by anger.

(Lilith) "You will pay for hurting my only friend in my life!"

Lilith has acquired Asura!

Asura

A title only brought into existence by a being of pure anger. It requires high intelligence, pure anger, and a title related to death. Grants the skill Asura's Wrath.

Asura's Wrath

Boosts all stats by 300% for 5 minutes, but the user loses all rational thought during said 5 minutes, all that matters is killing the enemy.

(Lilith) "You must die! Asura's Wrath!"

I start glowing with a pitch-black aura, my golden eyes become completely gold, and a black glow comes out of them. My scythe is twice the size and is glowing with the same black aura. 

Lilith's Stats under Asura's Wrath

Endurance: 76800

Attack: 173400

Defense: 73200

Magic: 85500

Dexterity: 135000