If you wear it will you be able to summon a dark portal to go to places? Or something different?

It protects you when you enter a dark portal. I don't think the Org. XIII coat lets you open a dark portal

It's kind of like the armor for Terra, aqua, and ventus. It sheilds them from the darkness when they pass through the dark portals.

It does not allow one to summon corridors of darkness, but instead, as previously mentioned, allows one to be protected from the darkness.

the reson they can sumon dark protals becausthear nobody when a heartless is darkenes thats why they can make portals

how come Kairi passed through one and she came out okay?

^ I think the light in her heart protected her so that she didn't need armor or a coat.

they dont need coats the light protected her

You can pass through a corridor without a coat, but it's dangerous to do so repeatedly.

Sora passed through one when he arrived at Traverse Town, for example.

You can pass through a corridor without a coat, but it's dangerous to do so repeatedly.

Sora passed through one when he arrived at Traverse Town, for example.

 

Isn't Sora's clothing magically enhanced? I know it is mostly for the different drive forms but I think the enhancement also provides some protection against the darkness which explains why is outfit is black like the Org 13 coat.

Sora didn't have magic clothes when he visited Traverse Town

so many questions and not many answers..

The coat provided protection from the darkness, as well as the ability to mask one from those that could otherwise "sense" them. That is why Riku wore one when he was doing stuff for Ansem the Wise.

 

Kairi could pass through them an unlimited amount of times, because she is one of the seven Princesses of Heart, whose heart is pure light.

 

All of this is explained already.