Annoyed Boona kept smashing away at the armour in front of her as Karst continued harassing it from the side.

Attack: 27 Damage: 12 + Smite 6 Radiant

Attack: 13 Damage: Unable to parse dice roll. + Smite 2 Radiant

Jurgen attacks the armor in front of him with staff alight with Green flame, which reaches out to the one next to it. 

Attack: 12 to hit with 10 bludgeoning damage and 5 fire damage
          - If that hit, then 7 fire damage to the one next to it. 

Bonus Action, Hero attacks the same one

Attack: 26 to hit with 5 Force damage

Fergus rattles the floating suit of armor with his discordant melody.

With Karst's help, Boona manages to get her maul past the empty warrior's defenses on her second swing and deliver a massively powerful wallop. If it had blood, it would be bloodied...

Jurgen swings his green-flaming blade, but the floating suit parries it. Jurgen's new automaton manages to connect with it, however, delivering a third damaging blow. 

Bryony, Jorzu, and Quinn may act.

"Beita þriðju varnaræfingunni!" announces the helmed horror in a calm voice.

For those who understand Dwarvish:

Quinn handily parries the armor's attack with his shield. His ears perk up as he hears the leader call out a new formation. Unsure of what's to come, Quinn refocuses on his target and he aims to take this thing down. The grizzled old ranger whirls Lightbringer above his head and he rains down a massive blow on his target. He caves in the help of the animated armor and renders it inert. 

Quinn spins on his heels and targets the only remaining target as his prey. He barks out to the crew. "Prepare yourselves! It's calling out another attack!"

He pounces on the suit of armor and lands another heavy blow with his mace.

Attack 1: 27 (NAT 20! + 7) for 23 damage (12 + 6 colossus slayer + 5 Hunter's Mark.

Bonus Action: Move Hunter's Mark to the leader suit of armor.

Attack 2: 24 to hit for 16 Damage

The second animated armor collapses to the floor in a loud, dented heap upon the delivery of Quinn's powerful swing.

Stepping over it, he then delivers a nearly as powerful, damaging blow to its levitating helmed leader. The armor is in very bad shape.

Almost fully surrounded, it calls out loudly in a hollow voice, "Innbrotsþjófar! Varnir brutust inn!"

Then it spins on Quinn with its arcanely-animated longsword:
Arcane Sword Attack #1 vs. Quinn: 26. Hit: 12 Slashing damage plus 7 Force damage. 
Arcane Sword Attack #2 vs. Quinn: 22. Hit: 8 Slashing damage plus 6 Force damage.

Everyone may act. 

In Dwarvish:

Jurgen moves and attacks the next armor with staff alight with Green flame, which reaches out to the one next to it. 

Attack: 24 to hit with 12 bludgeoning damage and 8 fire damage
          - If that hit, then 11 fire damage to the one next to it. 

Bonus Action, Hero attacks the same one, but misseS

Fergus:

With little else to contribute against a spiritual force unlikely to be moved by his persuasive abilities, Fergus sends another pair of discordant notes at the remaining suit of armor.

Radiant Notes (Starry Wisp):  Attack: 27 Damage: 17

Fergus' discordant note cannot seem to do any further damage to this construct, but Jurgen's fiery blade does. With a satisfying clang, the levitating suit clatters to the stone floor. 

Combat is over; everyone may act. 

Jurgen will ask if anyone was hurt and is in need of healing. If none, he would examine the suits of armor. 

Bryony gets hit once by the armor with the sword, but luckily it doesn't draw blood (temp HP!). She dodges the next attack. Before she can lash out with her blades, Jurgen finishes the remaining armor off with a blaze of his fiery sword. 

"Disembodied armor," the halfling remarks. "Or were there ghosts inside, and we couldn't see?" Not being able to speak Dwarvish, she has no idea what the disembodied voice had been saiyng. 

Shrugging her shoulders, she sets about investigating the room, looking for any clues that might shed more light on what was going on inside this place.

Investigation - 13

Fergus:

”They were animated by some kind of otherworldly presence, though it seems to be gone now,” replies Fergus as he looks around.  He examines the weapons and armor for signs of anything useful.

Perception:  21

(Edited to try and push through roll)

“The leader, the one with the sword, was calling out maneuvers for the other two.” 

Quinn walks over and kicks the sword out of its armored hand. 

“The last thing it called out was that ‘intruders breached.’ Not sure if it was calling out to anyone else nearby or if it was just following protocols.”

Quinn briefly looks at the sword to gauge its quality compared to the other equipment in this room. He also listens up for any other armor or threats approaching. 

Perception check: 13 

The three sets of plate armor, sized for dwarves, were not in great shape to begin with; now they are valueless except as scrap metal. The remaining weapons in the room, picked over by looters, are in even worse shape. There is nothing useful to you here.

This was clearly once a sparring chamber for dwarven warriors. It appears that the fighters who used this chamber didn’t only spar with each other; they also tested their prowess against these three suits of magically animated plate armor. But these constructs still stood ready to fight intruders, it seems. Now they are scrap.

All is quiet. What do you do next?

Boona absentmindedly kicked at some of the armour then moved over to push on the southern door experimentally with Karst beside her.

Fergus:

Following behind Boona to the southern door, Fergus says, "Well-fought, everyone.  I'll keep watch for any more ghostly apparitions," as he looks into the new area past the door.

Jorzu 

When its clear that the animated armour is finished Jorzu rushes over to the group. "I'm very sorry everyone. I knew to keep back from those things and thought I did. Apparently not far enough" he apologises sheepishly. "I do hope no-one was hurt. But at least now we don't have to concern ourselves with them attacking us from behind" he attempts to spin the event into a positive.

Jurgen keeps close to Boona. He smiles and says "You seem to find interesting people and things that want to do us harm. I think I'll keep next to you then."

Boona pushes open the southern door. It opens to another darkened room. A proper armory, albeit long looted. Other than a few broken shields and warped crossbow bolts on battered shelves and hooks, nothing of interest remains visible, at least from the doorway you now stand in. Jurgen and Fergus, small in stature, squeeze in behind Boona, in front of Karst, to look.

Quinn eyes the door to the east with concern. He drags what remains of the three mangled pieces of armor and stacks them in front of the door. He does not try to block it, but instead make it more difficult for something or someone to sneak out of that room and flank the group.

Quinn eventually follows the group and guards the rear while everyone else explores. 

Jorzu 

"Good thinking Quinn" says Jorzu as he enters the armoury. When he rounds the first corner a small squeal makes its way out of his mouth. Hes now surrounded by arms and armour on each side. Not wanting to set off any more arcane traps he moves slowly and deliberately down the exact centre of the room, eyes flitting side to side in anxious observation. When he makes it to the more open area to the east he stops dead and looks south.

Perception 20