The new McFarlane figures of GOT are fantastic.
Nevertheless, I am building LOTR armies, so want figures to match up with that. Stick to the plan!
Therefor I turned the Night King into an orc trooper.

I removed the spikes on the head, gave the skull a bit more mass and addes armour.
He now has shoulder armor, leg protection and lower arm braces. It is greenstuff over plastic.
Big issue was to keep it movable, so I sowed the pieces with needle and wire.
From the skirt I removed most from the front to get a better look when crouching.
Finally he got a pony tail, a bit Indian style.
And I gave more length to the ears to make them more orkish.
I used the original weapon of the Night King. Since this is made of ice, it was very bulky.
I sanded the thing down to make it more smooth like metal would be.
Also he got a new belt which would stand out more than the original one.
And he carries one of Legolas knives as a secondary hand weapon.

In the process, both hands broke of, so he has hands with screws to hold them now.
A solution I have to use with the Toybiz figures too.

Finally a thorough repaint. It became an interesting character!
Enjoy the outcome.