Katarina continues to do what raging Barbarians do best... hack and slash.

Longsword vs. zombie:
Attack: 14; Damage: 6 + 2 from RAGE!! (8 total, magical slashing)

Vanizi steps back as the creatures advance. She focuses on the zombie (green) Katarina is fighting, unless it has already been defeated.  If that is the case, she moves her Hex to the zombie (lt blue) beside Davis and attacks it instead.  With a few arcane words, she uses Eldritch Blast to send crackling energy towards the enemy. 
(Spell Attack: 16, Damage: 6 force + 3 necrotic) 

Davis will continue to attack the one to the right (lt blue), Unless someone has killed it. If that one dies, he’ll attack the one to SE (blue):

 Attack Warhammer: 13 bludgeoning damage: 14

Round 2:
Katarina rages on the green zombie before her, potentially returning it to the afterlife! (DC13 fortitude: 23)
Vanizi pops a blast of eldritch energy at the green zombie by Davis (unless for some reason the green zombie saved, then it goes to the light blue. DC14 fortitude: 5)
Davis attacks the swarm forming around him (light blue or blue), trying to prevent them from overwhelming him!
Halyqwyn 
Zombies:
Lt blue  
Red  
Yellow  
Blue   
Pink 
Green  

Round 2(con't):
Halyqwyn 
Zombies:
Lt blue - DC19 Fortitude: 5
Red  
Yellow  
Blue   
Pink 
Green  

Undead Fortitude. If damage reduces the zombie to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point instead.

(It looks like Lt blue went down for good?)

Seeing that these creatures could possibly pop back up, Halyqwyn is glad she can bring some radiant damage, hoping that makes a difference.  She targets blue, (unless lt blue is still up than that one), sending her sacred flame over that one.  DEX save 14 or 6 radiant damage.

Round 2(con't):
Halyqwyn sends a ray of radiant energy to the blue zombie (DC14 Dex: 18), burning the undead but not quite enough to kill it! (assuming it failed the save =)
Zombies:
Yellow  struggles through the grasping vines and roots to reach Katarina and attack her! (Attack: 22 Damage: 4)
Pink moves up to join the red and blue zombies to continue their assault on Davis! (Pink Attack: 23 Damage: 6: Red Attack: 21 Damage: 7: Blue Attack: 15 Damage: 5)

Round 3 - all characters up!

Katarina is growing increasingly frustrated at the refusal of the zombies to die... still... she's not going to stop hacking at them. She charges up to Yellow and slashes at it with her sword!

Longsword
Attack: 18; Damage: 9 + 2 (RAGE bonus damage) (magical slashing, 11 damage total)

Vanizi stays put for now, hoping the zombies won't advance any closer to her as Katarina and Davis seem to be holding them back.  Her attention shifts now to the creatures around Davis, as he seems to have his hands full.  She moves her Hex to the zombie (blue) that Davis is fighting. She then launches a blast of energy at the creature using Eldritch Blast. 
(Spell Attack: 17, Damage: 11 force + 4 necrotic) 

Blue DC20 fortitude: 19 - if it fails, Vanizi's eldritch energy attack drops another zombie! This leaves three - the yellow one fighting Katarina and the red and pink one fighting Davis.

Davis will yell back, “keep it up!” He will stay in front of the two zombies and will use his action to dodge their attacks.

Seeing that two zombies were surrounding Davis, Haly concentrates her light above the pink one.  DEX save of 14 or 6 radiant damage

Round 3:
Katarina slashes at the yellow zombie with her sword, chopping through decayed flesh but not ending the threat.
Vanizi's eldritch energy attack drops the blue zombie like a pile of dog poo in a bag with a hole in it! 
Davis uses his agility and size to his advantage, concentrating on avoiding the attacks of the monsters.
Halyqwyn drops more golden sunshine on the pink zombie... (DC14 Dex: 17)
Zombies:
Red  takes a step to the north and tries to slash at Davis, its mouth biting at thin air in a desperate hunger for flesh. (Attack w/disadv: 4 Damage: 3)
Yellow continues its assault on the giant kitty, although kitty isn't moving around as much as the little man!! (Attack: 7 Damage: 2)
Pink howls as it burns (assuming Haly hit it!) but is unwavering in its attempts to claw Davis.  (Attack w/disadv: 14 Damage: 3)

Round 4!

Cursing under her breath in frustration as the zombie deftly steps to one side, Haly tries again, sending her radiant energy down upon it.  DEX save 14 or 5 radiant damage

Davis will continue to stand with the zombies and dodge!

The raging Barbarian, getting truly sick of this stupid zombie, hisses in frustration as she swings her blade with all her might, completely forgetting caution and self-preservation in the hopes of finally killing the blasted thing!

Longsword (using Reckless Attack) vs. yellow
Attack: 9, 20; Damage: 12 + 2 (RAGE bonus) magical slashing, 14 total

Vanizi shifts her Hex the zombie (pink) that Halyqwyn is trying to attack.  She then launches another burst of energy with [spell]Eldritch Blast[spell].  
(Spell Ranged Attack: 25, Damage: 10)

Round 4:
Katarina is determined to slice and dice her way through the zombie in front of her! (Yellow DC19 Fortitude: 11)
Vanizi shifts her evil eye to the pink zombie and zaps it!
Davis continues being the halfling pinata to keep the mindless creatures at bay. (A great strategy, by the way. Take a point of Inspiration for good tactics!)
Halyqwyn keeps trying to target the pink zombie with her radiant attacks. (Pink DC14 Dex: 18)
Zombies:
Red  claws and bites and grabs at the shifty paladin. (Attack: 15 Damage: 7)
Yellow (waiting for Fort save results...) - drops dead once again!
Pink joins its decaying partner in trying to pin down Davis. (Attack: 12 Damage: 7)

Round 5!

Though wounded, he hasn’t been hit while evading, so he will continue to Dodge and hope the others continue to drop the zombies from afar!

Katarina smiles as the zombie FINALLY goes down... then immediately rushes forward, swinging on Red!

Longsword vs. Red
Attack: 19; Damage: 11 (9 + 2 RAGE bonus damage) magical slashing