Raktimos22, Kali21, TeslorLair, Carrhae19, Zippo19, TeslorLair, Mordok18, Sana17, TeslorLair, Yarog16, Zeada16, Teslor(AC22/345), Heren6, Surus4

Teslor swats Kali away.
Swat Attack: 21 Damage: 17

As the tail crashes into you, you stumble back and both of your feet fail to touch the ground at the same time during that moment as you flail back. Make a DC20 DEX save to take half or full of 23 damage. If you fail, you gain one stack of "Teslor's Curse". If you pass you only take half damage.

Raktimos22, Kali21, TeslorLair, Carrhae19, Zippo19, TeslorLair, Mordok18, Sana17, TeslorLair, Yarog16, Zeada16, Teslor(AC22/345), Heren6, Surus4

Let's fail this shit!: 25 

"Gonna take a lot more than that to knock me out of the park, you overgrown wyrm!"

Carrhae attacks the dragon twice!

Attack: 25 Damage: 19

Attack: 22 Damage: 20

Divine Smite: 8

The warlock moves away from the dragon while still invisible, getting further into the room but out of reach of the gargantuan creature. With a practiced ease, he twists two of his hands together and mutters the arcane phrase to activate the spell, attacking the dragon's intellect with his own. (Casting Mental Prison - take 17 psychic damage. On a successful DC18 INT save, the spell ends. On a failed save, Teslor perceives that it is surrounded by the creature or effect that burned its wings off!)

"Be trapped by this prison within your mind, blue one. A prison inside a prison, where there is only great pain and anguish for you."

Raktimos22, Kali21, TeslorLair, Carrhae19, Zippo19, TeslorLair, Mordok18, Sana17, TeslorLair, Yarog16, Zeada16, Teslor(AC22/303), Heren6, Surus4

INT save: 14 - Using Legendary resistance to autopass.

Teslor swats Carrhae away with his tail.
Swat Attack: 19 Damage: 20

As the tail crashes into you, you, too, stumble back and both of your feet fail to touch the ground at the same time during that moment as you flail back. Make a DC20 DEX save to take half or full of 44 damage. If you fail, you gain one stack of "Teslor's Curse". If you pass you only take half damage.

Raktimos22, Kali21, TeslorLair, Carrhae19, Zippo19, TeslorLair, Mordok18, Sana17, TeslorLair, Yarog16, Zeada16, Teslor(AC22/303), Heren6, Surus4

Sana pops compelled duel, pointing her sword at Teslor. "May Beshaba curse you, should you cross blades - or talons, or teeth, or tail or whatever - against any but me."

DC 17 Wis ST or he has dis on attacks on anyone but Sana, and can't move more than 30 feet away from Sana.

Then she attacks him with her gold-sparkling blade.

Attack: 24 Damage: 20

Attack: 14 Damage: 12

Smite for good measure: 4

Raktimos22, Kali21, TeslorLair, Carrhae19, Zippo19, TeslorLair, Mordok18, Sana17, TeslorLair, Yarog16, Zeada16, Teslor(AC22/303), Heren6, Surus4

DC17 WIS save: 17

Raktimos22, Kali21, TeslorLair, Carrhae19, Zippo19, TeslorLair, Mordok18, Sana17, TeslorLair, Yarog16, Zeada16, Teslor(AC22/272), Heren6, Surus4

Mordok has been standing there, slack jawed, as the dragon sloughed off the first attacks. Shrugging his shoulders in a 'why not' attitude, he quickly rages and recklessly attacks the blue beastie himself-

Attack #1: 16 Damage: 28

Attack #2: 22 Damage: 29

Polearm Master Bonus Attack: 24 Damage: 24

Frenzy Attack: 21 Damage: 27

Raktimos22, Kali21, TeslorLair, Carrhae19, Zippo19, TeslorLair, Mordok18, Sana17, TeslorLair, Yarog16, Zeada16, Teslor(AC22/220), Heren6, Surus4

Teslor swats away Mordok like a little flea.
Swat Attack: 17 Damage: 17

Oh that's awesome.

Raktimos22, Kali21, TeslorLair, Carrhae19, Zippo19, TeslorLair, Mordok18, Sana17, TeslorLair, Yarog16, Zeada16, Teslor(AC22/220), Heren6, Surus4

Zaeda grabs a flask from her belt and throws it towards Carrhae, "Here this should invigorate you." Healing word at 2nd level for 16. Turning back towards the dragon, Zadea hurls another flask full of green flames at the dragon, firebolt 16 for 18

Dex: 12

While keeping a solid distance(at least 70ft away) from Nikoli Teslor, Yarog breaks out a long, curled, and jeweled horn and belts out a long not upon it. With luck, his memory hadn't failed him. For soon after, appearing rushing out of the glint of light off an allied blade is none other than a green-skinned centaur as tall if not taller than Raktimos, bare of chest, but garbed in a battle kilt and shield. Without needing direction, he turns upon the dragon looking eager for battle.

Action: Cast (8th level)[Tooltip Not Found].

Grandpa Logic's Turn:

Grandpa Logic summons a mace to his hand, and with a cry of "Wa-ho, Vile Beast!" goes charging forth on all four horsey legs at the dragon on platforms of light and a golden gleam in his eyes! With every swing of it that connects, light scatters like sparks off the impact and surround allies close at hand in a protective aura.

Action: MultiAttack - Radiant Mace.
#1 Attack: 24 Damage: 12 of radiant to Nikoli Telsor. If hit, Grandpa gains the damage dealt as Temp HP.
#2 Attack: 24 Damage: 19 of radiant to Nikoli Telsor. If hit, Mordok gains the damage dealt as Temp HP.
#3 Attack: 18 Damage: 19 of radiant to Nikoli Telsor. If hit, Sana gains the damage dealt as Temp HP.
#4 Attack: 18 Damage: 13 of radiant to Nikoli Telsor. If hit, Carrhae gains the damage dealt as Temp HP.

Pic:

Raktimos22, Kali21, TeslorLair, Carrhae19, Zippo19, TeslorLair, Mordok18, Sana17, TeslorLair, Yarog16, Zeada16, Teslor(AC22/181), Heren6, Surus4

Multiattack
Frightful Presence: Each creature within 120 feet of the dragon and aware of it must succeed on a DC 20 Wisdom saving throw or become frightened for 1 minute.
Breath Weapon: Teslor, sick of your insolence, slams his claws into the ground and breathes, charging the entire lair with spine tingling electrical energy that surges over every surface in blinding power and ferocity. Everyone (yes, everyone) must make a DC23 DEX save to take half of 88 lightning damage. Then, make another DC20 DEX save to see if you gain one stack of "Teslor's Curse". If you pass, nothing happens. If you fail, or if someone has already failed, let me know.

Raktimos22, Kali21, TeslorLair, Carrhae19, Zippo19, TeslorLair, Mordok18, Sana17, TeslorLair, Yarog16, Zeada16, Teslor(AC22/181), Heren6, Surus4

Wisdom: 26

Dex:15
Dex:16

Wis: 23 I think I'm still immune since I saved and am near Carrhae

Dex: 28

Dex for curse: 12 using reaction to add 5 using flash of genius 

Oh boy.

Sana's saves:
Wis: 14
Damage Dex: 8
Curse Dex: 25

Heren's saves:
Wis: 21
Damage Dex: 15
Curse Dex: 16

SIGH

Heren poofs.

DC20 Wis save against frightening: 19

DC23 Dex save vs breath weapon: 23

DC20 Dex save against the lair: 20

Although Zippo managed to leap into the air in time to avoid the lair's trap, and even though he resists the worst of the dragon's breath attack, it still was way more damage than he could sustain after the rough trip through the first cube. As the electricity courses over and through the construct's form, he twitches on the ground for a several seconds and then lies motionless. 

DC20 Wis save: 22

DC23 Dex save: 18

DC20 Dex save: 30

Wis Save: Already under the Frightened.

Dex Save(DC 23): 11.
Dex Save(DC 20): 10.
Conc. Save(DC ???): 9.

Grandpa Logic, long may he do battle against the forces of evil, disappears in a flash of light the moment Yarog is shocked near inches away from death.

Wis save vs Fear: 18

Dex save vs. Breath Weapon: 6

Dex save vs. Teslor's curse: 16

So that's one stack of Teslor's Curse, frightened for a minute, and unconscious as horrible arcs of bright lightning wreak havoc through Surus's fragile form. 

Death Saving throw: 5