Gruntor takes his handaxe, and throws towards the creatures wings in an attempt to knock it down.  "A flying thing...smash them"

Attack: 11 Damage: 17   If he hits he will use a combat maneuver to knock the creature prone  DC14 strength save or be knocked prone.

Gruntor's mighty throw misses.

The cannon on Nasaar's shoulder sends a blast of force out at one of the flying creatures...

Attack: 22 Damage: 8

Then Nasaar lifts his heavy crossbow and takes a shot himself...

Attack: 22 Damage: 12

The creature is close enough that Nasaar's darkvision allows him to aim properly. Both attacks his and seem to injure the monster noticeably.

Next round starts. You hear more sounds, not from the skies, but also from the ground.

Serit, Firebolg, Gara are next.

(sorry, I spent almost the whole week without internet connection)

Hearing the sounds coming from the ground, Vrakskan tries to identify what's causing it. He lets the others deal with the flying one for now, as he isn't sure how to attack it in a way it can't backfire on him or the others.

Perception: 22

Vaskan identifies a number of scavengers nearby, slowly edging closer. There's a pair of mountain wolves, a flock of raven-like birds on the tree, and swarm of small rodents, looking like a mix of a rat a wolverine.

The firbolg growls to the mastiff, telling it to protect him.

((Are there any light sources currently? Firbolgs don't have darkvision...))

Vrakskan groans as he sees the wolves and the unknown rodents. While the birds could be related in some capacity to the flying monsters the others were currently fighting, these beasts could just be innocent wild creatures.

"We are not food, do not attack. It dangerous here." He says calmly to the wolves, approaching them without fear. He couldn't speak the beast's "language", but hopefully he could make them understand somehow to get them out of here without having to kill them.

Animal Handling: 6

The wolves appear to have a different opinion on the matter. With the tongues out and rows of teeth on display, they certainly appear to consider you to be on the menu.

@Firebolg. It is dark. If you need light, you will need to make one.

The firbolg curls his hand and flames lick up around it, illuminating the area. He calls his protective mastiff to his side.

Serit steps from his shadows and casts Mirror Image. And stands beside Vrakskan, facing the creatures he can reach.

Gara is next.

Gara will get close to the wolfs and distract one of them (Help Action to give advantage to the next attack against wolf #1).

He will order Efeu to stay close to Nasar. (Dodge Action for the steel defender)

What else can Gara see now with the fire up?

((It's only a 20 ft radius around the firbolg, so I'm not even sure if the firbolg has visual on the critters.)) 

Gara can see what Vraskan sees (nat 20 on perception let Vraskan see as much as was possible).

The flying creatures dive at Gruntor and at the Firebolg again:

Vs Firebolg:Attack: 21 Damage: 10

Attack: 10 Damage: 5

Vs Gruntor:Attack: 15 Damage: 10

Attack: 23 Damage: 5

Any successful hit from the creatures (first attack) does 10 extra damage.

((So firbolg takes 20 damage? He's almost down.))

Corect.

Vraskan, Nasaar, Gruntor are next.

AS the beast flies in at Gruntor and takes a swipe, he ducks low and counters with a swing from his scimitar

Spending one martial die for a Riposte attack as a reaction   Attack: 23 Damage: 16

The beasts second attack lashes into him deeply....ripping into gaps in his armor....

NOTE:  If Gruntor's riposte killed the beast than he doesn't take the second attack....

Gruntor will draw his second hand axe, now weilding both weapons, he will attack the flying beast....

1st attack with scimitar

Attack: 9 Damage: 10

If his opponent is dead he will move on to any nearest foe for the second attack

2nd attack with handaxe

Attack: 23 Damage: 10

Nasaar shoots at the flying creatures again...

Heavy crossbow to hit: 18  Damage: 10 Magical piercing.

Force balasti to hit: 24  Damage: 8 force damage

...