Rindarius quickly draws a dagger, and with a motion he's repeated and practiced thousands of times he spins the blade in his hand and hurls it at his target. This time, the target is the bandit.

• Ranged dagger attack: 14 | Piercing damage, if successful: 6

That hits the bandit and he shrieks in pain, he looks severily injured and turns on the direction of the attack, looks at Rin and can quite recognize him, but he does recognize Phrael and Flux - You!? I'm glad you are here because, it'll mean your death - says as he coughed blood

Flux's Initiative for next round:  2.

Flux had barrel in along with Kebron. But stops next to the door recognize the man for who he was. So THAT was what those tattoos were probably about... wait, didn't that mean Xoblob was... Flux's eyes went wide as the pieces fell into place. For both focus and need, Flux flares his cloak in the process of presenting his shield fully and chanting, "Grant us, 'ol wise watcher, your sight beyond sight, and bring about overdue justice!" 

Flux casts Bless on Phrael, Kebron, and Rin. (add d4 to attack and saving throws).

Don't forget that you do get advantage on surprise round attacks.

Initiative: 21

Notching another arrow, "Yagra gives her regards." Phrael takes aim. 

((I'll always consider that attacks are lethal unless stated otherwise))

Round 1:

A smirk crossing Phrael's lips as he thinks ahead to telling Yagra of this later just as he releases the arrow at the bandit. 

Attack: 16 +Bless: 1 Damage: 7

The bandit attempts to duck, but Phrael's arrow struck him in the neck before he could escape it's way.

Kebron charges the dwarf and swings at him with his axe

Attack: 13

Damage 7

That undfortunately doesn't hit, the gray dwarf manages to evade the axe and instead of counterattacking Kebron, laughs as he grows larger until his head is just a few inches below the cieling of the room (he is now considered Large) - I will crush you! -

(Assuming the gray dwarf's turn is complete)

"Should I be grateful that I now have an easier target?" comments Rin. The rogue effortlessly rotates his second dagger in his hand, finding the proper balance point, before hurling the blade at the newly-morphed dwarf.

• Ranged dagger attack: 15 | Piercing damage, if successful: 6

You feel how your hand is guided by a divine force (wether you believe in it or not, you've earned helm's favor) ((you didn't add the Bless and with that you actually are able to hit the dwarf))
The dwarf grunts as he receives the dagger and looks at you - Come and fight me like a man! -

Flux rushes up to the bandit if he hasn't fallen, and tries to put an end to him with his spear. However, if he is, enlarged Duergar becomes his target. "Surrender, Grey Dwarf! Or I will do what I must, as Helm commands." Flux warns after as he shifts around to cut off any room of escape to the south eastern door, if it hadn't already been blocked by its form. 

Spear Attack: 6 Damage: 6.

Don't forget Phrael that you can add your sneak attack to ranged attacks. Both Kebron and now Flux are in melee with it.

The bandit lies on the floor in a pool of his own blood - Pretty dead 

The dwarf is able to easily deflect your attack. - who should I strike first!? ha ha ha 

(I think you mean Rin, Ran)

(My turn?) 

The bandit dropping keeps the smile on Phraels face despite the gray dwarf's new larger appearance. 

"Get as big as you want..." Notching another arrow. 

"Aim small miss small." Phrael says as he aims at an eye. 

Attack: 15 +Bless: 3 Damage: 11

With little time to react to the sound of the speeding arrow, the dwarf only manages to catch the arrow with his left eye - Aaaarrg! What a bunch of wussies! - as he removes the arrow from what's left of his eye ((Even though he acts though, he is severely injured))

Kebron peers up at the enlarged dwarf.  Oi! What's the matter?  To scared to fight as a proper dwarf?  He swings his axe at the dwarfs knees in a attempt to knock him off balance.

Attack: 16

Damage: 5 

Will add Bless if needed. 2

Oof! you ain't no proper dwarf, I'll show you the power of Laduguer! - The dwarf raises an enlarged pick axe and attempts to attack Kebron 
Attack: 20 Damage: 6

Having thrown both daggers, Rindarius must either keep his distance or draw his shortswords and rush to Kebron's side. With swords drawn, the rogue leaps toward the over-sized duergar and slashes away...

With the second attack you manage to slash through the enlarged dwarf's stomach, his size goes back to normal as he groans in pain...finally dying after a couple of seconds.

You notice on the northeastern corner door barred with furniture and stuff and then 10ft south another door.