Ok, the pterafolk start to caw out again in common "Kill intruders! Defend nest!" They begin to fly and circle the pinnacle. I've added labels showing their position in the air. You can see that 2 of them make it to Eku and are able to make attacks (#2 and #4). The others remain at the top.

The 2 that make attacks are dive bombing towards Eku. Each of them make 3 attacks. They try and bite and claw at the couatl who is dodging. 

 Alton is up! Then Phillip, and then Eku.

Maps are updated. 

*Eku gracefully avoids all of the attacks!!!

So Evo would now be able to see those pterafolk in his viewline biting and clawing at Eku

(Evo, Azaka, Got-ipede, Aarakocra, Pterafolk, Alton, Phillip, Eku)

"Eku! Come down to meh!"

@DM...

((that is a great point, and something that I partially overlooked. Without giving too much away, the fire/light at the top of the tower is very bright. That's all I will say, and it does light up the top of the tower quite well. This is something that likely should've been mentioned earlier. As for the current battle with Eku and The pterafolk, the light from the top of the tower does provide enough light for that battle to happen, but if it goes any lower, the pterafolk will not be able to see and will likely not follow. Thanks Grwobert!))

((OOC: ahh! Say no more! That all makes sense. :-) Thank you so much!)).

Seeing that he doesn’t have much time before the next battle begins, Alton leaves his daggers for now, instead pulling out his light crossbow and loading a bolt. 

He then moves two spaces to the left on the map (next to Philip), and will use his action to hide in the nearby shadows. He is prepared to shoot at the first sign of a pterafolk from his vantage point.

Stealth: 18

Phillip calls to Evo (who he thinks maybe has a decent view up), “Mister E’vo? Mister E’vo??... Are they coming down? Is E’ku okay? Hmm??.....”. He sees Gotur’s centipede-form disappear off and sees Alton arrive nearby. He’s confused as to what to do, but then as an experienced climber his mind is made up...

”Mister E’vo!... A’lton! I’m going up the chimney! Uh huh, uh huh!... Yell if you need me!... I‘ll try to either ffff-P’ight them or ‘ffff-P’lush them down’!”. And with that, he stows his weapons, pats Alton on the shoulder and dashes off to get as far up the chimney as he can...

Movement and dash action: to get to the chimney and scale as far up as he can. ((Total distance (25ft + 25ft) = 50ft, whether he’s walking or climbing))

He’s trying to get as far up as possible, but stopping before getting within 10ft of the exit. In reality he’s probably about half way up?

((Not sure Evo has an time left for more talking this round? Phillip probably hears him yelling to Eku though.))

((Hehe- Yes I half-realised that. Just for RP/flavour more than anything... ;-) He made his own mind up in the end!))

Alton quickly takes out his crossbow and sneaks into the shadows against the stone wall. Should any pterafolk fly down to this level, he will be hidden from them. 

Phillip, you indeed make it exactly halfway up the chimney! You actually make it directly behind Got-ipede and you both are in the same spot in the middle of the chimney between levels 3 and 4. 

Eku glances down at Evo who has just asked her to come down. She says to him, telepathically, after evading all of the pterafolk's previous attacks. "I don't think I can get away safely. But don't worry about me, friend." she flaps her wings and snakes through the air and then tries to latch her fangs into pterafolk #2. Attack: 11 Damage: 10

The fangs nick the creature but still rips into its flesh. The pterafolk now also makes a CON save... 14

and that's a fail. The pterafolk starts to froth at the mouth and becomes poisoned from Eku's bite. This poison renders the creature unconscious, and it therefore falls close to 300 ft down to it's death. 

Round 4: Evo, Azaka, Got-ipede, Aarakocra, Pterafolk, Alton, Phillip, Eku

Evo is up! Map is updated. 

"It was more so aye could do something!"

Evo sends the magical spirit mace up 20ft towards the fight and guiding bolts the other pterafolk he can see.

Guiding bolt:Attack: 21 Damage: 15

Evo, the mace is now 20 ft up from the 3rd level (10 ft away from Eku). The intense light from your magic then races towards the pterafolk that is engaged with Eku and it slams into the creature. The creature now also seems to be glittering slightly so the next attack roll on this pterafolk will be with advantage. (#4)

Azaka now follows through with what she said to Got-ipede and she follows him and Phillip up the chimney. She still has the magic effects so the climb is easy for her. She climbs up to just behind Got-ipede and Phillip, so halfway up the chimney. She says quietly "Gotur, Phillip, thank you again for helping me in my quest. I shall not forget this." So the order of the three of you in the chimney is shown on the map, with the giant arthropod leading the way.

Got-ipede is up! 

(25ft from the opening at the top)

Evo, Azaka, Got-ipede, Aarakocra, Pterafolk, Alton, Phillip, Eku

Maps are updated. 

Got-ipede scuttles up out, shifting to half-orc form and calling down to Azaka. 

"Get up and out, into the tower! I'm gonna have to drop your climb to be able to cast!"

((Is the crowned one on the ground or in the air? If it won't get a swipe at Gotur, he'll dash for the tower. He doesn't want to drop concentration, so if he can't get to the tower safe, he'll hold action to dash in once Azaka is in.))

((I think all the pterafolk were 10' up is what Klein said.))

The pterafolk at the top level are indeed 10ft up, and therefore the 'boss' would not be able to attack Gotur as he shifts back to his half-orc form and heads into the tower. 

The aarakocra starts to caw at Alton, quite frantically now. It also tries to escape the ropes a third time: 13

and the aarakocra breaks free from the ropes!!

Actually... before I process the pterafolks turns. Spider, the pterafolk that are at the top will see you change into the half-orc and run into the tower. Well, at least the boss and #1 will see you. So the boss wouldn't get the reaction attack, but since it's their turn now, they may or may not try and attack you as they've seen you run into the tower. So when you say you would only do it if it's 'safe', does that mean not getting the reaction attacks, or does it also mean you don't want to risk getting attacked by the pterafolk on their turn?

Let me know and then I'll process the pterafolk's turns!

Also, if you drop concentration, Azaka still can climb the chimney, but she will have to instantly make a check as the magic dissipates from her body. 

sorry not instantly but on her turn if she continues to climb

((Actually, can I have had him scuttle to the tower as Goti-pede, instead? I missed that Azaka had just started climbing the chimney. He should have 15 ft left once inside, are there any windows looking out, or places he could have a good view of the surroundings besides the door?))

((that is totally fine, those 2 pterafolk will still see you scuttle into the tower though.))

As for what you notice in the tower and in general as you reach the top of the tower: The spire’s pinnacle is flat and roughly 40 feet square. The edges are crumbling away. Vines and low brush grow in profusion. Bones and scraps of meat from dozens of creatures are scattered everywhere. A crumbling stone tower rises another 30 feet above the northern corner of the platform. A roaring flame floats in the air, hovering above the tower. 

Inside the tower, there are no windows other than the top section (check out the 'Firefinger' tab). Also inside the tower are crude nests and four moldy wooden chests.

So, Got-ipede is in the tower. He may or may not get attacked by the pterafolk who saw him scuttle in there.

Let me know if that is all good Spider and then I'll make the pterafolk turns. Just trying to avoid having top make retro turns!

Yep, that works.