Though on his last leg one noble Sunbro makes his triumphant march to a new position, praises the sun, and unleashes a new miracle onto the battlefield to restore as much vitality as he could in the heat of the moment.

Movement: KL-13 (or alternate position to get at least Selherac and Boom within 60ft of Abe).

Action: Cast Mass Heal on Nox(if applicable), Tupoc(if applicable), Selherac, Boomshakla, and Self, restoring the following amount of HP, and removing any disease or blinding effect:
Nox: 81 HP.
Tupoc: 8 HP
Selherac: 210 HP
BoomShakla: 126 HP
Self: 146 plus an additional 11 from Blessed Healer feature.

OR(If unable to get at least BOTH Selherac and Boom within 60ft of Abe this turn under any circumstances - See Spoiler)

 (@Lerus: The non-spoiler is preferred if at all possible. But, I was a bit uncertain if I math'ed out the positioning of everyone right to make it work. So... would it be possible to get in a decent position for it?)

TUPOC

Tupoc flies as fast as he can and closes in on the dragon from an indirect angle {KD26, 30 feet from the ground}. From his new position, the monk also lands three strikes, knowing that each one has pulsed within the dragon's body successfully (Ancient Red Dragon takes 28 magical bludgeoning damage).

LEGENDARY ACTION

Lysanderoth whips its tail at Selrahc:

-> Tail vs. Selrahc: Attack: 28 Damage: 16 bludgeoning.

The barbarian feels the sting of the whip-like tail across his arm (Selrahc takes 10 bludgeoning damage, already halved).

Selrahc Retaliates with another slash (Ancient Red Dragon takes 29 magical slashing damage).

ABE

Abe runs to a more central position and unleashes a powerful healing spell. Almost all allies feel the warm touch of Lathander. Tupoc has flown a bit too far and Yessaris is visiting another plane.

(@All: Healing amounts copied below for convenience).

(@Ori: No amount of re-positioning will be able to include Tupoc, I'm afraid).

END OF INITIATIVE ROUND 7

INITIATIVE ROUND 8

• 24. Nox - concentration on Wall of Force, benefiting from Aid (4th level), Mage Armor, Mirror Image (counter: 9), and Contingency (Dispel Magic); 
• 21. Yessaris & Attorney - concentrating on and benefiting from Haste (counter: 9), benefiting from Blink (counter: 4) and Aid (4th level); Attorney is also benefiting from Aid (4th level);
• 20. Lair 
• 17. Ancient Red Dragon  
• 12. Tupoc - benefiting from Aid (4th level), and Empty Body (counter: 3);
• 12. Selrahc - benefiting from Animated Shield (counter: 4), Haste (counter: 9), and Frenzied Rage;
• 11. Boomshakala - concentrating on Haste (counter: 9), benefiting from Aid (4th level);
• 04. Abe - 

SHOWDOWN!:

(Nox and Yessaris are up next).

Seeing her companion moving east she misty step (bo slot usage due spell mastery) at KG-13. Detecting the dragon she cast Toll the Dead at it WIS DC 19: On fail 19Necrotic damage.

Yessaris reappears 10ft closer to the right and glaring down at his chest. "... I don't have time for this. Chiffon! Activate Emergency Temoregulators." He says to the shield, causing the extend barrier projection to turn an ice blue, and frost begin forming on both it and the rest of Yessaris' form. "Attorney! To me!" He then commands as the rapier is once more lashes out in a more strafing strike. 

Bonus Action: Command [Tooltip Not Found].

Action: Casts (4th Level)Thermoregulator Protocol on Self, choosing the Chill Shield option.

Movement: To KK-25.

OR(if unable to reach using below prescribed in spoiler)

Hasted Action: Defender Rapier - Attack: 22 Damage: 11 of magical piercing.
Using Defender's Ability, removing the +3 to the hit to add +3 to Yessaris AC, making it 28.

[Tooltip Not Found] Turn:

Movement/Action ([Tooltip Not Found]): Dash to KG-22, leaping as appropriate onto and off the rock.

(If an Athletics:(30) still needed for at least the jump off the rock platform.)

(S/N: Above post is subject to change based on any Movement Based Legendary Actions Following Nox's  Turn)

End Turn:
Ethereal Jaunt Protocol(DC 11): 15.

"Etheral Jaunt Protocol is....unable to activate" some device on Yessaris' person speaks up, eliciting a small sigh of relief. "Small favors."

Future Reaction(Yessaris): Cast (1st level)Shield if applicable for an 'attack' that's 32 or less, if caught in Breathe Cone or other saving throw and would fail by 4 or less - using Flash of Genius to pass.

Future Reaction(Attorney): Deflect Attacking, inflicting disadvantage on the 1st Attack on an Ally.

NOX

Nox escapes her own trap and notices the large dragon. She reacts by casting Toll the Dead:

-> Ancient Red Dragon's WIS saving throw {DC 19}: 28

The spell has no effect.

LEGENDARY ACTION

Lysanderoth reacts by beginning to beat his wings:

-> DEX saving throw {DC 25}, Damage: 19 bludgeoning

• Selrahc: 15
• Tupoc: 27
• Fall damage: 12 bludgeoning

Selrahc is hit by buffeting air (Selrahc takes 9 bludgeoning damage, already halved), while Tupoc is hit by the actual wing (Tupoc takes 9 bludgeoning damage, already halved). Both warriors are knocked prone, and the monk falls from the sky: (Tupoc takes an additional 5 bludgeoning damage, already halved).

Lysanderoth flies 40 feet into the air, enabling an opportunity attack from Tupoc.

(I'll resolve Yessaris' turn next).

YESSARIS

The artificer walks a bit east and enables his Chill Shield. He commands Attorney to follow on his footsteps and the constructs can soon be found on the other side of the lava river. 

Yessaris does not disappear this time.

(@Ori: You can no longer reach the dragon for that Hasted action attack. Do you want to do anything else with it?)

(Lair goes next).

LAIR

Magma erupts from just below Abe, shooting upwards and damaging the cleric:

-> Abe's DEX saving throw {DC 15}: 21, Damage: 17 fire

Abe is caught by surprise (Abe takes 19 fire damage).

DRAGON

Lysanderoth loops backward and releases its fire breath from above the eastern bank of the lava river:

-> DEX saving throw {DC 24}, Damage: 110 fire:

• Abe: 15
• Nox: 10 - this roll becomes a 26 (reference)
• Selrahc: 13
• Yessaris: 28
• Attorney: 18 - this roll becomes a 24 (reference)

The fire is simply too hot, heavy, and fast-moving. Most of those targeted feel the full effect of the explosion. Abe hugs the wall but it is for naught (Abe takes 92 fire damage). For a moment, Nox wishes she had not left her cube, but even then, manages avoid most of the burn with the help of her Absorb Elements spell (Nox takes 23 fire damage and is affected by her Aversion to Fire racial trait). Selrach sees many of his wounds reopening (Selrahc takes 92 fire damage). Attorney almost comes apart but dodges the threat by following his master's orders (Attorney takes 46 fire damage). Yessaris was ready for it, letting his shield absorb some of the explosion (Yessaris takes 23 fire damage).

-> Nox concentration check {DC 11}: 24 - Wall of Force is dropped

-> Yessaris' concentration check {DC 11}: 34

Now that the Dragon finally took it to the air, you can see its hoard in full splendor. In addition to a sea of multi-metallic coins, many precious items seem to be carefully placed within the hoard.

-> Lysanderoth is at the {KG30 - KL35} diagonal (a 6 x 6 square).

(Tupoc, Selrahc, Boomshakala, and Abe are up next. Tupoc has a pending opportunity attack. Yessaris has a pending Hasted action).

 Nox lucky roll on dex 24 save: 9
If there still damage after the save Nox activates Absorb Elements with her reaction.

Tupoc takes a strike at the Dragon and, seeing what it is planning, attempts to interupt with a blast of Ki (Stunning Strike).

Attack: 30 Damage: 11; DC 19 Con Saving Throw or become Stunned

Boom knows his fragile body could get destroyed by this dragon at any moment so he goes for broke.  Boom flies up vertically 30 feet making the distance between the dragon and he smaller.

A frigid beam of blue-white light streaks toward the dragon as Boom uses Ray of Frost

Hasted Action(Addendum): Loading Overrule with +1 Bullets to capacity. 

Movement(Yessaris-Addendum): To KG-27.

Reaction(Addendum): Flash of Genius on Attorney, adding +4 to his Dex Save vs Breathe, raising results to {24}. New Damage Taken: 46.

"As Predicted. ATTORNEY! The Treasure Dune-...." More formulas float into view and mind, slowing down time from the Battle Smith's perspective. What take the best of the average minutes if not hours to calculate, the Yessaris solves in a split second. "-to the Left!" He barks out as he snaps his frozen shield in the anticipated path. Trusting its master implicitly, Attorney dives part way into the treasure side, realizing only how much of the less easily melt-able items had been placed there.

After much patting off a flaming bum... and pretty much everything else, Abe turns and realizes a good number had hoped over. He starts to do the same, sees how far he'd jump a second time, and with a curt "Nope!", begin racing his way around to a safer locale for now. "Try...hang on... friends! It's... too.. far! Need... to take... detour!" He calls out breathless during the run. After eventually getting to temporary cover, he calls once more upon the Morning Lord for aid, mending at least some of his burns.

Movement: To KI-10.

Action: Channel Divinity - Preserve Life on self, restoring 29 HP.

Bonus Action: (5th level)Healing Word on Self, restoring 32 HP.

(S/N: Above subject to changed based on any movement prior to Abe's turn.)

Selrahc will take a couple steps toward the dragon, not wanting to get close just in case it breathes fire on him again.

He will take the Dodge this turn. Not much he can do when the creature is in the sky.

Reaction: Retaliation/Sentinel: Attack: 25 Damage: 25

RESOLVING PENDING TUPOC'S ACTION

-> Before the dragon releases its breath weapon: Tupoc's opportunity attack hits (Ancient Red Dragon takes 11 magical bludgeoning damage).

-> Dragon's CON saving throw vs. Stunning Strike {DC 19}: 34

-> Dragon uses its Legendary Resistance to overrule that Nat1.

RESOLVING PENDING YESSARIS' ACTION

Yessaris reloads his firearm with magic bullets and climbs the pile of treasure the Dragon was sitting upon until recently.

(I'll resolve Tupoc's, Selrahc's, Boomshakala's and Abe's turn separately next. Others have already posted but Tupoc is still up).

Tupoc shakes his head from the impact as the dragon continues to fly away. “I could have sworn I felt that one take, but no matter. Everyone look out... too late.” The monk launches himself into the air to chase down the dragon as it carpet bombs his allies, ending around KG-31. He makes another three quick strikes, bashing fists against the hard scales. 

Attack: 29 Damage: 8 

Attack: 27 Damage: 13

Attack: 27 Damage: 15

TUPOC & SELRAHC

(@Hydra: The dragon is occupying your intended square, so I am moving you a bit).

The monk takes it to the air once again after falling to the ground last time he was hit by the Dragon. He flies forward, now in the air at {KF-31}. He delivers three more punches to the enemy, but only one takes hold (Ancient Red Dragon takes 12 magical bludgeoning damage). Tupoc remains nearby for follow up attacks.

Selrach also gets a bit closer, but not too much {KK-24}. He raises his gigantic axe in front of him in preparation for any other fire breaths.

LEGENDARY ACTION

Lysanderoth whips its tail at the flying monk:

-> Tail vs. Tupoc: Attack: 23 Damage: 22 bludgeoning.

Remaining in the air after being hit is not an issue this time, but the Couatl-hybrid still feels some pain (Tupoc takes 9 bludgeoning damage, already halved).

ABE

(@Ori: Your intended square is a massive wall -- the dark red splotches on the map. Assuming you are favoring cover rather than maximizing the targeting of your spell, I'm moving Abe to {KI-9} instead).

Abe finds a place he feels better protected and engages in some self-patching (Abe heals for a total of 61 HP).

LEGENDARY ACTION

Lysanderoth whips its tail at the flying monk once more:

-> Tail vs. Tupoc: Attack: 34 Damage: 19 bludgeoning.

Another passing sting tries to catch the flying monk's legs, but he pirouettes out of the way.

(Boomshakala's turn needs to be reconsidered before we can move forward).

Edit:  I'm dumb and forgot deleting the disintegrate damage would give the manipulation error.  Here is a clean roll.

Attack: 16 Damage: 26