Thri-Kreen's and two weapon fighting with dual wielding (and nick too)

I've seen a couple posts here talking about how two weapon fighting, dual wielding and nick interact with one another, but there wasn't really anything mentioning Thri-Kreen.

The dual wielding and light weapon extra attack attacks are considered separate attacks as far as I am aware.
What I wanted to have a bit clarity about as how it would interact with a Thri-kreen, which has double the amount of hands as other species.

For example:

A Thri-Kreen that is wielding on their;
1st Hand: Battleaxe (topple)
2nd Hand: Either empty, a shield, or battle axe being held with two hands.
3rd Hand: Scimitar (nick)
4th Hand: Scimitar (nick)
,has the Two Weapon Fighting Style and the Dual Wielder (2024) feat.

How would the weapons function together, if the Thri-Kreen used their attack action to attack with one of the scimitars?
What would be the ruling as to how what weapon is part of the attack action used, and what would be in the bonus action?
Would it be possible to use the battleaxe?

Thanks in advance

Thri-Kreen have more hands than most people, but that doesn't give them any special ability to attack more times or anything like that. I don't think anything about any of these rules would change for Thri-Kreen.

In this example, when taking the Attack action, the Thri-Kreen could attack with either the battleaxe or one of the scimitars. However, since the Battleaxe isn't Light, attacking with it wouldn't allow them to then make a bonus action attack via either the Light property or the Dual Wielder feat, as both of those require taking the Attack action and attacking with a Light weapon first.

If they attacked with one of the scimitars as their Attack action, they'd then be able to make an extra attack due to the Light property, or Dual Wielder. Having the Nick weapon mastery would allow them to do both. Those extra attacks could be with the other scimitar, or (for the Dual Wielder one) with the battleaxe.

Yeah. The only thing that more hands gives them is the ability to take advantage of DW's ability to use better weapons without having to swap weapons.

Quote from jl8e >>

Yeah. The only thing that more hands gives them is the ability to take advantage of DW's ability to use better weapons without having to swap weapons.

 Also holding a Shield all the time. I know some DM's will allow weapon juggling to dual-wield one-handed, but there are also a lot that won't (though it is allowable RAW, I presonally think it is aganst RAI). Thri-Kreens don't have to worry about it - they can go it like a buggy blender and shred things.

Thanks for replying,

So from what I can understand, what the Thri-Keen can do;

1. Attack action to attack with scimitar
2. As part of the same attack action, thanks to nick, attacks with other scimitar
3. Uses dual wielder to attack with the battleaxe using a bonus action

Did I understand correctly?
Also would it be able to swap the order of the second scimitar and the battleaxe? (scimitar → battleaxe (bonus action) → scimitar 2 (nick)) Or would using the battleaxe second mess up the nick?

Yes, the first attack enables the extra attack of the Light weapon (modified by Nick in your scenario) and also the extra attack from Dual Wielder. For both, you need a different weapon from the one that enabled the extra attack, as is the case in your example.

But... using the Bonus Action in the middle of your Attack action is something that has been debated in the subforum. I think it's legit, but not everyone agrees. See, for example:

- Page #2 in About Dual Wielder + Nick (New perspective)
- This comment in Grim Hollow Feat "Lightning Caster". I added some related threads in my reply.

Quote from auroracavelier >>

Thanks for replying,

So from what I can understand, what the Thri-Keen can do;

1. Attack action to attack with scimitar
2. As part of the same attack action, thanks to nick, attacks with other scimitar
3. Uses dual wielder to attack with the battleaxe using a bonus action

Did I understand correctly?
Also would it be able to swap the order of the second scimitar and the battleaxe? (scimitar → battleaxe (bonus action) → scimitar 2 (nick)) Or would using the battleaxe second mess up the nick?

As Tarod said, it's not super clear whether you're allowed to take a bonus action in between multiple attacks in an Attack action, so that might be something to check with your DM about. If I'm DMing, when the rules say you can make a certain set of attacks, I don't care what order you do them in, even if some orders aren't technically allowed. 

If  I understand this thread, the Thri-Keen in spite of all the hands has the same "result/process" as a two handed individual.  There is no difference to include wielding a shield?

Quote from Character77006 >>

If  I understand this thread, the Thri-Keen in spite of all the hands has the same "result/process" as a two handed individual.  There is no difference to include wielding a shield?

The capabilities of the Thri-Kreen's extra hands are laid out pretty clearly in the book that introduced them to 5e (Spelljammer: Adventures in Space). They cannot wield shields in those extra arms (though they can with their normal arms) but they can wield Light weapons.