The story starts and some flashbacks from the previous movie sequel of black panther are shown as how T challa wanted to share Thier resources with the government of the outside world , But few of Wakandian oppsoses this decision . 

And other characters known water livings which were lead by the NAYMOR, visits Wakanda as he thought that Wakanda is giving and sharing vibrannum to the outer world and this could be so dangerous for those water livings and wakandians too ..

So , NAYMOR kidnapped the Shuri (she was sole daughter of the Queen 👑) and wakandians tries to search for Shuri but they can't get too deep into the water , NAYMOR tries to explain how dangerous it would be for Wakandian and Water livings , but wakandians accomplished in getting to Shuri under water by mean of some tracker in Shuri suit ....

 And then ,  Shuri goes to Wakanda and try to explain this to her wakandians leaders and they're also happy at this decision but by some kind of mistake (mis-happen)  NAYMOR gets news about them as they're denying that and then Neymar against goes to the Wakanda with his army and destroy it ...

But now , Wakanda wanted to retaliate and so Shuri works in her lab and succeeded in making that herb which changes normals to the black panther powers and she ate it and made a suit and also became a female black panther for her tribes and for Wakanda ..

So , then Wakanda warrior goes in water for fight and it was about impossible to defeat water livings in the water or near the water and by some tricks Shuri succeeded in taking Neymar to the desert island and to that island Neymar became less is powers and Shuri almost killed him and they both by somehow succeeded, and fights between both water living and wakandians have been stopped and now they started to live as a friend's ....

My favruote Scene 

Sources Link