The thing that makes it really upsetting is that this skin isn't thematically different from his base skin. The other two ultimate skins were pretty different thematically from their normal ones.
Sona gained a more high-tech version of her normal theme, giving her the standing of a DJ. It's not too different, but you could put them side by side with their descriptions and I could definitively say which one is normal.
Pulsefire Ezreal may be closer to his original theme, but it gives so many different random features like upgrading armor, special death emotes for enemies, etc. that it's definitely okay for an ultimate skin. Plus, it's like DJ Sona in that it high-techifies the champion involved while still leaving the very base theme. Once again, you could put them side by side with their descriptions and I would be able to tell which one was normal.
But then you get Spirit Guard Udyr, who is a visually enhanced version of Udyr with better spell effects and features that could easily go onto his base skin. Seriously, all he has other than new spell effects is extra stuff when you max the ability. That's just lame. And, given a description of Udyr, I would not be able to tell which one was his base skin. I can't think of one thematic difference between this skin and his base skin, and that's just unacceptable for something this pricey.