I haven't gotten giant rage Unikitty, but it does look to have ball joints in a bunch of places. Any articulation issues would be more along the lines of spikes blocking the range.
The spikes aren't a major problem, they are on clip joints, thus move out of the way when you bend the legs, the spikes around the side of the head move along with the head which is on a ball joint, the paws can move up and down, for the most part, its feline body movement style, the tail can move about as that's on ball joints, the shoulder connections to the body are where the ball joints are, overall its a reasonable range of movement but no human arms out poses due to desgin but that's fine with me as its meant to be a four legged creature, you can do a full 360 on each leg as the spikes at the side of the head move about to be however you want them to be! The front shoulder pads are on clip joints so their not in the way, there's two spikes on the back of the body that can move up and down and cover where Emment can stand or someone else, say for example a lego Zombie!
Well hopefully tomorow, I'll do some major repairs to my big lego castle, its gotten a bit wrecked by my six year old nephew while I've been at work, the front needs serious repair, so its a scenic ruin, currently, plus I plan to add to large base boards I bought a while back to the two already in place, hopefully that make it a bit more stable, it will take a while to sort out as I get the walls repaired and the top part of the front gate fixed! I think my nephew is curious to how cullis the gate part works that or he obessed with destorying it as apart of whatever game he was playing, this includes taking the tresure out of the chests and leaving it scattered everywhere, I'm thinking of moving the chests over to my dark fortress and say the bad guys stole the tressure (he doesn't play with that model as its elsewhere and not in the room where he its aloud to go!)