Pizazz's Ravenloft and Beyond

"Don't kill marked one, he's our bounty!" wanted to say Ulthan but his mind faltered and instead at 8 let's loose two arrows against the stupid guy that spoke. You never give orders when others hear you, all goliaths know that dumb giant elf howdah carrying uhm elf.
Attack: 17 Damage: 22
Attack: 15 Damage: 17

Cat bounds and leaps on the same elf at 18
Claw: 27 Damage: 12
If it hits with claw make DC 13 or it goes prone. Unless it's a giant dragon. If prone, it gets an auto bonus bite attack Bite: 19 Damage: 9

At initiative: 23 Mordekai will cast Disguise Self to make similar markings to Meepo's recent tattoos appear in his skin, not just immediately appearing there, but emerging with a momentary glow, almost as though they could've been there,  dully, all along, but had flashed more vibrantly with the new arrivals (not sure how much control Mordekai has over how the spell emerges, or whether the glow is more of a giveaway to the Illusion rather than just catching their eye, but if needed, Deception: 28).

Then Mordekai starts to run, 30ft away from the giant-riding elves (and in a direction away from Meepo).

Init: 14

Ketch thinks and says nothing, nearly grabs shield and axe and starts hewing down the closest giant…

Giant Slayer Axe Attack: 19 Damage: 6 PLUS 11 slashing damage and if hit giant must make DC 15 Str save or be knocked prone.

Bonus action War Priest allows second attack, also with Giant Slayer Axe:  Giant Slayer Axe Attack: 17 Damage: 9 PLUS 3 slashing damage and if hit giant must make DC 15 Str save or be knocked prone.

Divine Strike adds 4 to whichever hits, if either.

Meepo initiative: 21

Meepo frowns at the giants and elf and casts fireball to hit as many of the giants as he can at once...

DC 16 dex save for half, otherwise take 31 fire.

(It seems we really have to)

The forested cross roads is in-amidst some short cliffs. The four giant-with-an-elf-on-its-back appear in each cardinal position around the group. The one to the east is up on top of a cliff about 30 feet high, and is otherwise 35 feet from Meepo, the closest party member to it. The giant-elf to the north is about 20 feet from Mordekai the closest party member. The giant-elf to the west is about 40 feet from Ulthan, the closest party member. The last giant-elf is 30 feet south, closest to Lionel. 

Meepo, you'll only be able to catch one giant-elf in a fireball given the way they've appeared from around you. 

Let me know if that changes your action or not. 

Round 1:  Meepo 23 | GE4 21 | GE3 17 | Ketch 14 | Mordekai 12 | GE1 12 | Lionel 9 | GE2 9 | Ulthan 6

Mordekai's action stands - and afterwards, he'll run east-ish, fairly close to the bottom of the cliff wall below G3.

((Ketch will still swing twice with the Axe but as GE4 & 3 go before him, Ketch will move in to attack whichever GE is closest to Meepo, not necessarily whichever is closest to Ketch himself.))

Giant: Dex 16 : 10

Elf Dex 16 : 20

Meepo spins and a fireball arcs up to the giant and elf standing on the cliff above him.  The fire roils around them. 

The southern most giant is quick to move, stomping over the fallen trees and past branches, his club at the ready to swing at Lionel.  It swings its club at Lionel first... Attack: 23 Damage: 20  and then affixes Lionel with an oversized, beady eye.  Lionel feels waves of evil flowing over him. 

Lionel, Charisma DC 14 save. 32 psychic damage, save for half.  Meanwhile, the elf atop the howdah releases a roiling cloud of magic across the group. 

Everyone, at the start of your turn, DC 14 Con save as the air around you fills with poison.  19 poison damage, save for half. 

The giant at the top of the hill fixes his evil eye upon Meepo. Meepo, Charisma DC 14 save. 27 psychic damage, save for half. The elf on his back holds up his hands, and tries to pull at the fabric of the world. (1 he is successful : 1) A fabric of darkness tears open and some large dark shadowy thing slips into the world.  

The shadowy demon creature flies down the cliff face and to Meepo, and begins striking at him. Attack: 13 Damage: 14

Ketch, do you attack the shadow thing that is attacking Meepo then?  

DC14 CON save: 8

Mordekai casts Hellish Rebuke as a reaction against the elf that cast the poison spell. DC18 or take 12 Fire damage. Half on save. 

Lionel Cha save: 25  Con save: 10

Unless G1 kills Lionel on spot at his turn, Lionel will hold G4 (the most southern giant). Or, better say, his rider:

Action: Haste self

Haste action: Attack: 11 Damage: 8

Ketch would still attack Giant closest to Meepo, what with having a Giant Slaying Axe and all...

Con Save: 5

So actions as previously stated.

Meepo cha save: 9

Ketch glances around. The closest giant is probably the one to the north, and his axe would like to taste some giant blood!  He rushes forward through the hazy poisonous smoke, coughing in pain as it seeps into his lungs, and then rushes just outside the edge of it, next to the giant, and attacks. 

(Strength DC 15 : 15 and again DC 15 : 20 ) 

He slams his axe into the giant, blood spraying from the creature, the axe almost singing in his head. He swings again, and more blood as the giant is rocked. On the second hit the giant stumbles back and crashes to the ground, the elf leaping free of the howdah as it's crushed, but hitting the ground hard for 6 damage. 

Mordekai meanwhile unleashes black flames of rebuke against the elf in the Howdah. DC 18 save 19

Then Mordekai casts his illusion, the shimmer of the scrivener tattoos appearing on his flesh with a flash.  All of you...even Meepo are confused for a second, so convincing is his act.  Ooooh, HE'S the one with the tattoos...right...not wait...no...it was actually Meepo...wasn't it?  

He rushes for a gap between the giants, and all eyes follow him. Even the shadow sent to fight Meepo looks after him, then back at his "boss", as if silently asking, 'did I get the wrong guy?'. 

Another of the giants advances, trying to get close to Ulthan, but standing...waiting....his huge club at the ready, waiting for Ulthan to emerge from the poisonous cloud so he can bonk him.  The elf meanwhile attempts to summon his own demon... (1 is successful : 1 ) ... but fails, as his attempt to pull open a shadowy portal fails and it seals shut. 

Lionel casts haste on himself, and tries to attack the giant in front of him, but through the cloudy poison is unable to hit. 

The giant up by Ketch growls in pain from the two blows, and pushes himself up to standing, then swings his club down at Ketch. ...

Attack on ketch: 26 Damage: 21 

...and then affixes Ketch with his bulging mishapen eyeball ...and Ketch feels an evil power swirl within him.  DC 14 Charisma save or 32 psychic damage. half as much on a save. 

The dark wood elf on the ground pushes himself up and backs away from Ketch and the giant as they fight, and tries to also summon a shadow demon. (1 is successful : 2) 

Which he does!  A shadowy demon pulls itself free of the portal and lunges towards Ketch. 

Attack on Ketch: 11 Damage: 11

Meepo screeches as his body distorts in a mishapen way, one shoulder hunching upwards, the other down, and one leg turning to the outside as the giants evil eye fills his form with a curse. (While deformed, the creature has its speed halved and has disadvantage on ability checks, saving throws, and attacks based on Strength or Dexterity. The transformed creature can repeat the saving throw whenever it finishes a long rest, ending the effect on a success.)

Ulthan, you can't see anything in this poisonous fog, so you can't take your shots. What do you do for your turn?  (and Con save please) 

Round 1:  Meepo 23 | GE4 21 | GE3 17 | Ketch 14 | Mordekai 12 | GE1 12 | Lionel 9 | GE2 9 | Ulthan 6

Ulthan missed as above but he moved his 30 feet out of the poisonous cloud north east towards least amounts of giants. Poison save 17.

Ulthan charges through the poisonous smoke, crashing through some bushes at the base of the cliff, emerging from the green smoke coughing slightly as he glances around. 

Meepo's action. Meepo, there's a shadow attacking you, and you're surrounded in green poisonous fog, you can't really see much in any direction. (Con save) 

Ketch Charisma save: 18

And I am assuming elf fell on far side of giant so Ketch gets no opportunity attack as it moves away...

Meepo con save: 26

(I am assuming this poison cloud is like fog or darkness, that you cannot see through it, thus Misty step will not work here. If that is the case I also assume that the shadow will not get an attack of opportunity against Meepo as he moves away, as vision is impaired inside of the cloud. If that is not the case, then might have to refactor what I am doing below...)

Meepo moves out of the fog of poison air, stepping away fromt he shadow facing him. As he steps free he lifts his wand and points it at the most injured-looking elf among the elven members facing them. as he does so he uses the wand to cast finger of death on the elf.
DC 18 con save for half, or take 59 necrotic damage.