Lucas faced the group and said, "I was traveling from the North with five human rangers. They were seasoned hunters and trackers... The best in Ror'nav. I suppose was the odd one out with my devilish looks and all, but we got along well. They didn't deserve to be murdered by mindless minions. They were good people just looking for some adventure and coin."

Lucas grimaced as he focused on Lord Orbid. 

"Orbid had his townsfolk slaughter us in our sleep after we turned in for the night at the inn. I was the only survivor. We did not provoke anyone during our brief stay..." 

Pointing his axe with one hand in Orbid's direction Lucas shouts, "I don't see anything but selfish evil in front of me..."

"Well if you'd like to see your companions, all you had to do was ask."

With the snap of his fingers, two doors on the second level and three on the ground level swing open. Behind the doors stands your traveling companions, Lucas. The two on the second floor have bows and the ground floor individuals are brandishing a mixture of dual swords and sword/shield combinations.

"Guards, take care of them!"

As he gives the command, he pulls a piece of leather from his robes, begins gesturing his hands, and speaking a quick phrase. A wave of bluish green energy washes over him before fading.

Roll initiative!

As the battle seemed inevitable, Sieghart unsheathed his second blade and prepared for the engagement.

Initiative: 8

Arlo looks to the archers as he starts putting a plan into action

initiative 10

Happy knew something like this would happen. 

Initiative: 5

Catherine nods in agreement with Lucas. She isn't one to be cowed into submission, nor to make deals with an enemy.

"You'll get naught but the bite of my axe, fiend."

Initiative: 11

Initiative: 11

Initiative order:

Lord Orbid

Catherine

Arlo

Happy

Sieghart

Guards

Lucas

Lord Orbid moves left and down to the square directly below the second archer and points his finger at Arlo with a flourish and accompanied by words. A sickening ray of greenish energy lashes out.

ray of sickness: attack 7 damage 11

If it hits, please roll a DC 14 Con save or be poisoned until the end of your next round

Catherine, your go!

Catherine charges after the sorceror with a snarl, determined to bring him down quickly.

(Dash action to move next to him--I believe she has exactly enough movement to catch him with 60 feet)

(With the dash action you have plenty of movement)

A slight expression of concern washes over Lord Orbid's face as he sees the enraged, well armed woman charge up the stairs to him.

Arlo, your go!

Arlo runs up after Catherine, and gets to just next to the archer and Orbid. Then he starts swinging his handaxes at Orbid.

Attack: 18 Damage: 3

Attack: 10 Damage: 5

Your first swing meets a little resistance as it makes contact with a magical barrier that becomes even more evident when it flashes. You give a little extra effort and are able to cut into Orbid. Making note of that, you take your next swing and easily break through the barrier and into him.

Happy, your turn!

Happy moves to the square in front of Sieghart and castst Eldritch Blast at Orbid.

Attack: 16, Damage: 1

The crackling beam of energy streaks from your hand, through the second floor marble railing spindles, and strikes Orbid in his shoulder. He takes the pain with a grunt and bares his teeth in your direction.

Sieghart, your turn!

With Arlo and Catherine fighting at close range against Lord Orbid, Sieghart decides that shooting with his bow is too risky. He runs at the bottom of the left staircase to make sure  he can obstruct the passage for the guards. He enters a battle stance, ready to parry or dodge incoming attacks.

(Action : Dodge)

You ready yourself for what is to come.

The guards jump to the call of their master. The archer next to Arlo flips his bow around and attempts to push him over the railing to the steps. 

Strength (athletics) check: 11

Arlo, make an athletics or acrobatics check, your choice, to prevent being shoved over the railing.

The archer on the other side of the hall will attempt to shoot Catherine in the back

Attack: 9 damage: 2

The guard with the sword and shield rushes at Sieghart and attempts to cut you down

Attack /w disadvantage because of dodge: 16 damage: 3

The dual swordsman on the right attacks Happy while the other advances on Lucas.

Attack on Happy: First sword 13 second sword 15 Damage: First sword 2 second sword 4
Attack on Lucas: First sword 12 second sword 23 Damage: First sword 3 second sword 3

 Lucas, your go! 

Arlo athletics check 8

Arlo gets shoved back over the railing and down onto the steps. Roll a dexterity saving throw to keep yourself from tumbling down the stairs (should have asked you to roll this along with your athletics check)

Lucas, feel free to post your turn before or after Arlo makes his saving throw.

Lucas is stunned as his former friend slashes him in the arm and torso. Badly wounded, he snaps out of it, and attacks the ranger in front of him with his axe in both hands. 

Attack: 3

Damage 11

Your axe cuts through him with little resistance. Darkened blood gushes out as he slowly collapses.

Lord Orbid is going to take two step away from Catherine and cast ray of sickness again.

Attack: 18 damage 5

Catherine, also make a DC 14 Con save or be poisoned until the end of Orbids next turn.

Lord Orbid will then continue to make his way down the walkway, away from Catherine.

Catherine, your turn!

An arrow whizzed by your head, Arlo was just shoved over the railing to the stairs, Lord Orbid exposed his defenses as he put some distance between you and him, then fired a sickening green ray of poison at you before continuing to widen the gap. The poisonous magic took a toll on you, but your anger and determination are stronger than what he has. You have your reaction to take before any effects of the ray of sickness, but your next turn will be subject to disadvantages should you fail your save.

Also Arlo needs to make a dex save.