Woah. A+ for complicated. C- for organization.
Let's start here.
As much as you may know about the game, your figures seem vastly overpowered to be competitive. (Real shocker, I'm sure). Anyways, it's best to use would like high, medium, or low extra damage that scales with AP, AD, etc. This let's the professionals do the professing, and keeps your ideas, well, ideas. Now that that's out of the way, here are some of my aidea for your character to give it, well, character.
First, if you are going to call your concept, "Shujinkō, The Anime Main Character," and give virtually no frame of reference for what that means, you kinda failed from the get-go. If you think they are just going to cast him blatantly as an anime character, you are dead-wrong. League of Legends cares very much about their lore, and, though a skin voption may allude to some specific character, the backstory should come as an interesting as an addition to the already vast League of Legends Universe. So do your homework, get to know the game in depth, and then actually create a legend.
As far as your combat structure goes, I hope you appreciate the time I am putting into this to give your little guy a chance, because right now he just looks like, "Spammy McSpammerson, who even spams dying." For example, your Q may as well be bonus basic attack speed, and it definitely can't be enough to get to an attack every .5 seconds (alone, at least). Plus, you can forget about a 50% bonus on top of that. I believe the max attack speed in the game is every .2 seconds, but minimum is about an attack every 1.75 seconds (variably). So I think you see why starting off with double the attack speed of all the other champions doesn't work. Besides, what exactly is the point of changing the trajectory when the next attack is almost immediately after the first? It is pointless.
Next, I think your W may as well be that passive, considering there is really nothing there (you only care about yourself you little faker). However, I think the idea of a passive that activates by being around allies and gives secondary effects on abilities would be unique and is a good idea with the right tweaking. Speaking of which,I hate to break it to you, but what we have here is a support and not an ADC disguised as a, "Fighter." since your character is centered around the idea of having allies nearby, healing, adding damage, and doing cc, the good news is you have the bones for a pretty good support, and a passive from nearby allies keeps a beginner support where they belong in-game (which is around as many allies as possible).
Conversely, your passive idea feels like a W that should be active before you die (and not after), and that allows it to potentially heal an ally, instead of worrying about yourself and still being killed four times. For it to be practical in any since, you would have to knock it down to maybe 4-6% (more likely off of base health rather than max/ current, as those can overfluxuate) and allow, say, 4-6 stacks, so it gives you something like a nice 24% heal every 24ish seconds.
In regards to how the healing activation procs, I'd definitely make it an icon dropped from nearby slain enemies which you could passively pick up, and actively use as a W for healing in a support role, and I think that is a good thing, because A) Consistency and B) Tankiness (which I think was the idea) and C) The pleasure of having something to do while your supporting by running back and forth trying to appear scary in bottom lane (and I believe they always try to make support as fun as possible). This would also be eliminate typing random letters to and trying to come back from the dead ('cause it sucks).
Now, back to basic attacks. Would they be ranged or melee? Because it sounds like you want to build a ranged character, and, if so, a Q that buffs ranged attack speed/ damage would be a nice utility for procking an item like Spelltheif's Edge, or could find synergy with Ancient Coin, as both of these are optional items for support. Meanwhile, the knock-up Idea screams support class, and your W would be even better as a passive in a support role.
In fact, if you want my personal opinion, I think your passive could include secondary effects on all your abilities (since they seem to be multifaceted) and, though somewhat complicated, I see potential for it in team fights, especially when you are a player down and need to rally in a 4 v 5 scenario. I'd also change the secondary effect of your ult to a sheild which could helpp in regards to chasing that guy who barely made it under turret with 5% health, or saving your teammate who thought he could dive on three people by himself (only to end up crawling back to the team like a loser exboyfriend). I would do this especially because two abilities effecting attack speed sounds excessive.
Finally, since this is clearly a support, the takedown idea kind of falls right off. You already have enough going on with your W, which I think should be reworked in some manner to be a passive. In the end, I think what you have here is a Nami/ Leona who gains some teeth in mid-to-late game team fights without being too strong in early-game jungle ganks and bottom laning.
