Amelie LookAStar Review

My first note, before delving into the kit, is that the "forever protected" angle doesn't really work well on an ADC; if you were to correctly sell the "I am protected always" angle of your thematic, you might run into the issue of getting rid of a lot of the vulnerability that comes with being a Marksman, which can be REALLY SCARY. Marskmen are designed to stay squishy and *mostly* immobile, because they sport both superior range and damage as compared to the rest of the cast, along with the ability to depend on manaless damage. If you disagree, that's fair, but my own opinion (which is also the general opinion) is that this isn't something that should happen.

Anyways, your passive is neat in that you have the "guardian spirit" thing, which I assume the "forever protected" thing comes into play. Thematically, it's pretty cool, but the actual mechanics behind it isn't something you can really control, taking the skill out of your own skillset. It's also very incidental, because it can block either a Pyke R or Cho R and punish them heavily, or block an auto attack when you're at 5 HP, or block a Veigar R when you're half HP. It's not really something that's super consistent, unlike a straight-up shield-- but then, it still ties into the issue of "automatic and artificial safety without any skill". The buff you get along with it also doesn't make much sense, as it actively rewards you for going low on HP and being about to die-- but, chances are, if you're about to die, you won't be able to get the enhanced ability off in the first place. It's also just not as clear as "gain a shield when low on HP", or "revive every X seconds when you die".

My biggest issue with Q is that it's three different interesting (or semi-interesting) on-hit passives tied into the space of one ability. That's both a LOT OF COMPLEXITY and A LOT OF INVISIBLE POWER, save for the third toggle. You've also got a point-and-click stun on an ADC, which is pretty horrifying (Supports are there for a reason; ADCs and Marksmen are designed to not make picks as well as other Champions and not be able to self-peel; for reference, Ashe is defined as "that ADC that has reliable CC", and has to trade off a lot of the damage most other ADCs have for it). There's also no reason for the fourth to exist, unless it consumes mana, which isn't listed.
With the additional effects, because it's an auto attack instead of an ability cast, you actually lose a lot of control over it-- along with making it clunkier, because, to get the correct effect, you might need to mill through all the other effects first, which could feel awful.

The W is fine, but it doesn't really feel impactful, and doesn't really work well with the rest of your kit as this is the only part of it outside of the passive that feeds into the "safety" angle-- but it also doesn't tie in with the idea of your spirit protecting you. The passive effect also doesn't make much sense, in my opinion, as it's just "more damage". A lot of potential complexity is lost to your Q.

The E is also fine, but the passive effect doesn't make much sense in my opinion, as it shares the same role as your W's effect of "instant damage". Again, a lot of complexity is lost to your Q. It also shares the same thematic role as your W, which is "explosive arrow".

The ultimate isn't very interesting, as it's just a big steroid. The passive interaction is also kinda awful, as you want to pop it at the start of every fight, as opposed to popping it when you're one hit away from death-- and, at that point, it might as well pop automatically.

To summarize: there's not much skill expression in your kit, as everything boils down to "AoE damage abilities" or "augment your right clicks", and there's not actually anything here that says "protected by a guardian spirit" outside of your passive. A lot of the skill in an ADC is also poured into how well a player can position, which is partially taken away by your passive (which is often useless). Your ultimate is, thematically, the spirit talking to you and giving you strength-- but a steroid ultimate like this can be spun any way and convincingly sell the idea of being strengthened by your guardian spirit. A lot of complexity is lost on your Q, as well, which pulls away from the rest of your abilities, which could potentially be REALLY COOL with this thematic. It's also not very DIRECTED; your passive is a defensive ability, your W is a ward with AoE damage, your E is basically an AoE auto attack, and your R is just a steroid. Every Champion has a niche, but this feels kind of all over the place. Your spirit is also almost never involved in the actual kit and what you do, leading to a worse Lamb and Wolf problem than Kindred has, where one of the two is supposedly always there but never actually doing anything that feels impactful.
I think that the "flexibility through enhanced arrows" also meshes poorly with the "spirit archer" angle, and they're both fighting with eachother a bit here.

As a next step, I would look to pick either the "enhanced arrow archer" or "spirit archer" thematic, and then scrap the other, along with picking which parts of your kit are the coolest THEMATICALLY and gutting the majority of the mechanics in favor of something both more skill-expressive and cooler. The concept of "spirit archer" is fantastic in my opinion, but the mechanics in place you have now with a lot of your abilities restricts a lot of what you can do with it to get it there.