If she's not by the constructs, or what remains of them, she moves there. She will keep firing arrows until the thing decides to go toe to toe with her.

Oathbow Attack1: 9 Damage: 15

Oathbow Attack2: 19 Damage: 16

Chill's bolt strikes as does one of Rhogar's blasts.  Kazri again demonstrates her affinity for the oathbow as she strikes twice.

The dragon suddenly exhales a ray of radiant energy in a 120-foot line that is 5 feet wide. It blasts into the remaining medium construct destroying it.  Kazri is also in the line of fire

Kazri - DC 16 Dexterity saving throw, taking 21 radiant damage on a failed save, or half as much damage on a successful one.

1

Krom is up

Rnd 5

Chill, Rhogar (bless), Kazri, Dragon, Krom, Vellynne (bless)

The dragon flies 90 feet closer to Kazri.

Kazri DEX Save: 10

(Adding +3 due to Aura of Protection)

(Does Shield Master Evasion works here?)

(Shield Master Evasion - If you are subjected to an effect that allows you to make a Dexterity saving throw to take only half damage, you can use your reaction to take no damage if you succeed on the saving throw, interposing your shield between yourself and the source of the effect.)

"At least they helped us in getting the dragon's attention." says Krom as the last of his constructs is destroyed by the dragon's energy breath. Paying particular attention to not stand too close to the rest of the group, the dwarf keeps sprinting west. "If the dragon keeps staying out of reach, I'll soon will not be able to channel the All-Father's blessings." Krom points his hammer aiming it at the creature's head and chants once again an hymn of evocation sending a powerful radiant beam towards it.

Movement
10Ft West

Action

Guiding Bolt at 2nd level Attack: 20 Damage: 17

Quote from Wolfy911 >>

Kazri DEX Save: 26

(Adding +3 due to Aura of Protection)

(Does Shield Master Evasion works here?)

(Shield Master Evasion - If you are subjected to an effect that allows you to make a Dexterity saving throw to take only half damage, you can use your reaction to take no damage if you succeed on the saving throw, interposing your shield between yourself and the source of the effect.)

 It would if you were holding your shield, but you are using a bow right now so you can't use your shield.

Kazri dodges out of the way and while some of the radiant energy washes over her the resistance granted by her deity leaves her nearly unscathed (5 hp damage - I noted it on your sheet)

Krom sends another bolt which hits as Vellynne follows up with another Chill Touch

Chill touch - Attack: 19 Damage: 9

Chill, Rhogar and Kazri are up

Rnd 6

Chill, Rhogar (bless), Kazri, Dragon, Krom, Vellynne (bless) Medium construct (HP 9 AC 13) 

(DUH!!)

Chill continues taking steady aim (BA) and fire at the dragon.  How much more can it take!

Attack: 25 Damage: 32

"Keep doing what you can, Master Krom! But if need be, leave the rest to us 'till the abomination flees or lands." Rhogar called back to the dwarf, then took a deep breath expanding his chest to near cartoonish before unleashing another divine breathe weapon blast at the dragon, lighting up chinks in its armor.

Action: Cast (1st level)Divine Breath at Dragon.
(Lethal)Guiding Bolt - Attack: 1+15 Damage: 14 of Radiant.

Quote from Paladin54 >>

The dragon flies 90 feet closer to Kazri.

Does it mean now that if Kazri moves 10ft, she will be within melee range?

Its still in the air but headed straight for you.  You could ready an attack as it looks to be coming at you to attack.

(Works for me.) Kazri puts away her bow, and readies her Dragon Slayer sword. Since she is not carrying her shield with her, she holds the sword with both hands. "Here, I challenge you foul creature!!" She brings the sword high hoping to really get its attention.

If the dragon comes within melee range, she will attack with her sword.

Sword Attack1: 25 Damage: 21

Sword Attack1: 19 Damage: 24

Kazri drops the Oathbow and draws her sword.  But she finds it is strangely heavy and her heart yearns to take up the bow.  She realizes too late that she swore an oath to the bow and now her use of any other weapon is hindered giving her disadvantage on her attacks

Disadvantage would apply but your first roll is straight due to Rhogar hitting with Guiding Bolt giving you advantage and the second is already a miss so no need to roll second d20s

The dragon crashes straight into Kazri, slashing with its claws and whipping its tail around to strike at her.

Attack: 27 Damage: 16

Attack: 20 Damage: 11

Attack: 17 Damage: 19

Additional wing attack

Attack: 28 Damage: 13

Kazri must also make a  DC 16 Wisdom saving throw or be charmed by the dragon for 1 minute 

Krom, seeing that the dragon has accepted Kazri's challenge and entered the paladin's melee range, charges the creature swinging his war hammer with all his strength "Your trail of destruction ends here!" 
The dwarf also chants an hymn of evocation summoning a shimmering hammer. Swinged by an invisible hand, the hammer is smashed against the dragon's head.

Movement (if required to reach melee range): 10ft towards the Dragon

Action (if 10ft are not sufficient to reach melee range, I'll dash instead of attacking)
Attack: 15 Damage: 11 + 7 of Fire Damage thanks to Divine Strike

Bonus action

Spiritual weapon Attack: 25 Damage: 10

(Darn last clauses!! Rolling with disadvantage going forward.)

DC 16 Wisdom saving throw or be charmed by the dragon for 1 minute 11

The malevolent presence of the dragon washes over Kazri and Krom as they are within 30 feet of it as it lands to attack Kazri.  Kazri resists the charm of the dragon but Krom falls under its spell.  The dragon immediately directs the dwarf to attack Kazri. His hammer rings off her armor.  Krom then casts his spell and strikes the dragon with the spiritual form of his hammer.

Krom DC 16 Wisdom saving 23

Krom shakes his head clear of the spell the dragon had on him as Vellynne continues casting Chill Touch

Chill touch - Attack: 25 Damage: Unable to parse dice roll.

Chill, Rhogar and Kazri are up

Rnd 7

Chill, Rhogar (bless), Kazri, Dragon, Krom, Vellynne (bless)