Pls note this is my preferences as a potential reader. Pls don't take it too seriously 
Guard of sight (8/10)
So this one is probably my favourite design. I like the design cuz it's very simple, even the colour palette is nice. Im weak for character that have a long piece of clothing like scarf
Guard of hearing (7/10)
Design wise, it looks good but there's something about her makes me feel like something isnt enough. I guess it's just my preferences but it's feels basic. I would love to see another types of musical note on her design such as Breve
Guard of taste (4/10)
I don't like her design at all, personally. I don't understand why grapes? Tbh for me, those two colours doesn't match well since its too bright. If you darken it a lil bit, it would work. She fall flat for me cuz of the sweater? At the front. It doesn't give me the same vibe as others
Guardian of smell (7.5/10)
The design is great since Gaia looks like one of those tarot cards symbol(?). Idk what to say about this one that much but I like it.