This is a feedback post, I will give my feedback about Olaf's shield here even though I know that nothing will be changed.
Visually speaking, this circular shield looks very strange, and out of the place. I know it's the easiest and most practical solution, but with so many circular champions/items shields within League, Olaf could be given a more unique shape.
The blame for this strangeness comes a lot from Olaf's silhouette. Olaf's stance in the game is very hunched forward; the axes are outside the shield; there is a lot of shield-free area behind Olaf; That is, it is visible that this shield does not belong to Olaf\*.
You guys could see the possibility of changing this VFX to look something like an aura shield-like Sejuani-Bristle (Fury of the North), Malphite (Granite Shield), and Olaf himself in his ultimate (Ragnarok), but instead of this shield being "glued" to Olaf's body as in the examples cited, Olaf's shield could visually function as an "electrical aura" coming out of his body. Contouring Olaf's body using his silhouette with 2 times (maybe 3 times) the size outside the body, thus giving an impression of protection/shield, as if his body was protected by a shield of electrical rays.
*Olaf's shield in-game:
https://pbs.twimg.com/media/FQKzjPiWYAklNNh?format=png&name=large
https://pbs.twimg.com/media/FQK0BCKXoAIHtLS?format=png&name=large
https://pbs.twimg.com/media/FQK0b_TWQA8mz-6?format=png&name=large
https://pbs.twimg.com/media/FQK08ffXIAsh46g?format=png&name=large
https://pbs.twimg.com/media/FQK1i_IWUAgGGvC?format=png&name=large
https://pbs.twimg.com/media/FQK17dQX0AgsCrr?format=png&name=large
Passing this to the artists. Not sure whether they're going to change anything, but they'll see it.