I don't know why I never though of this before, but the thematic of the champion fit so well with the project theme. A warrior who uses the spirits of the animals to a monk like lifestyle, makes so much sense to be studied and reconstructed in the future as a project. I don't know exactly the lore of project, but that's what makes it cooler. I don't know if they are the actual champions rebuilt from augmentation, a suit for a normal human to become augmented, or a fully reconstructed robot.
But Udyr fits so damn well for a project skin. They could put good effort into it and make it 1350, maybe 1820 if it was the highlight. He could have lights all over his body, at the start of the game they are off, whenever he enters a stance the lights change colouse and his suit could slightly change formation. Blue for bear, green for turtle, red for phoenix, yellow for tiger.
Like it literally fits so well with him I don't know why it isn't considered. If it was 1820 I can already think of some interactions and lines. Maybe he could start going on about the spirit of the animals and then become conflicted with the fact that he is a robot now. Or maybe his suit could be powered by Udyr's animal connection.
As for the model I think he should look fairly beefy. Not thin like Fiora, more of a tanky spiky sort of feel. His Tiger Stance could maybe have a little light with a PROJECT Tiger on the back and light up yellow on all his colour windows, whilst making claws come out of his hands kind of like a robotic Wolverine. His W could summon a Project shield, light up a turtle on the back and make green appear on the colour windows, maybe some kind of skirt like armor could come down further, to mimic his normal skins. His E could beef up his arms and lock his fists into a shape, light up a project bear on his back and make his lights go blue. His R could light up a phoenix on his back, make his lights go red, and his suit could open and extend wing like things around his arms and could either emit red glowing energy or fire, energy sounds cooler.
As for the sounds, I can already hear them in my head. You know the sound of a spring getting magnetized or a spring in like a storm catcher, kind of tinish sound? That could play whenever he switches stances, in his Q when he does his fast slash, it could play a kind of sound like PROJECT: Ashe's Q sound. His W could make some really generic shield activation sound, I'm sure they would come up with something, his E could play a sort of project Ekko E/Q sound when he stunned someone, and his ult could make a sweeping sound similar to Camille's W or something, and he could push his hands forward.
On top of that everytime he entered a stance, a pixelated animal sound could play, like it was through a loudspeaker or something. This whole skin just seems like it fits Udyr, all the effects would be straight forward in the design process, I know Riot does Project skin every year now, even though I am posting this in OCE I hope that they consider Udyr for a candidate as even though he isn't really meta he does need a new skin by now, he hasn't had one in ages.