Unbalancable
Right now several champions, I believe, fall firmly into the category of "Unbalancable". There is no way Riot could adjust those champions to be both healthy, and viable. Rakan, as a support is a prime example. Rakan has a shield passive, about 60 Health at level 1 from its base value, plus the AP he gets from sorc tree, which makes his trade potential very high, and his early risk very low. His Q is a decently ranged poke ability, that provides Shields AND heals for himself AND an ally. For a few references, soraka, an entirely heal based champion, gets less healing in lane, and it COST health from raka. Oh and "Decently ranged" is 900 Units. If that means nothing to youi, compare it to blitzcrank Q, which is 925 units. Which means, this champion out ranges blitzcrank hook. While still freely harassing. The projectile speed is actually faster than blitz hook to. Its also faster than Zyra Q, Soraka Q, Alistar W, Veigar Q, Ashe W, Tahm Kench Q, Velkoz E and Q, Xerath E, and most auto attack animations. Which means that, from outside of most ranges, Rakan has a dual sustain ability that allows him to positively trade any poke at a range most champions can't respond to, at a speed most champions can't dodge early. If blitzcrank hook can be hard to dodge in the LCS, and its the number one priority in lane, then how is it acceptable that rakan Q is harder to dodge, when it gives so much.
You may think that "well if its such a consistent ability, there is some trade off. You know, nami is really reliable, but her cooldown and mana costs are pretty high." well you'd be wrong. Rakan Q costs 60 mana, he has 8.8 as his mana per five, and base pool of 315. All these numbers go up with levels, plus Coin and Frost Fang both give lots of mana. Thresh, is a champion who has to go coin line because of mana issue. Rakan doesn't need coin, but goes it anyway, because it has no downside to do so. Rakan never runs out of mana, or health with his Q, and can positiviely trade, basically forever. As long as he's not spamming it at full health, its ridiculously efficient. Oh and by the way, the bonus from fairy revitalize, and overheal, all apply on Rakan Q. It can shield for about 150 additional health on an ally plus the 50 health it healed for (at rank one, its quituples by rank five, or level 9)
"Sure his Q sounds a little over loaded, sure but come on man, its like his core ability. Its his identity as a champion. Don't yu think thresh hook being a dash and a stun and displacement is a little powerful too?" Actually, wrong, its not his core ability, its the simplest and smallest ability on his whole kit.
His W, is a dash, that also is a knock up (after a delay) that has AoE only 50 units less than Maplhites ULTIMATE ABILITY and is the same size knock up. Mana cost is 50, less than his Q, despite being a large impact mobility and CC (like idk blitz hook or Leona hook that takes abut a 1/3 of their mana level 1) oh and, unlike Leona, Blitz, or Alistar, Rakan doesnt max his major CC ability. Thats right, it remains nearly as effective as it already is level one until teamfight time, by which point rakan will have CDR and be at least level 9 and begin maxing his W second. Rakan gets to maximally utilize his impact play making ability, without sacrificing his power to trade in lane. If you care to notice, Thresh's passive on flay (E) has the icon for his hook (Q). This is because it was far too efficient for thresh to be able to max Q, and get maximum use out of his hook, while also having high trade potential due to what is now his E passive. A high skill, almost all skill shot, high channel time, playmaker support doesn't get use of his poke and trading in lane because its too strong, and then Rakan gets to maximize his lane poke and sustain, which thresh doesn't even have any sustain, while also having big CC impact and EASIER SKILLS TO LAND.
His E is battle dance, he can dash to an ally like Lee SIn, sheilding himself and that ally like Lee Sin, oh also it has more range than lee sin. Level one the sheild is about 80 health. To him and an Ally. So 60 effective shielding. Oh then he can do it again. So, Rakan dashes to an ally, eats the CC for them, then dashes back to the ally, and gets out, as if eating the CC didnt matter. But don't stop there, because doing so didn't exhaust all his resources, because he picked up a sheild on the way in, oh and he has his passive, oh and if you jumped on him, he got his Q shield, about 160 health worth of sheilding at rank one abilities, oh and he got heild for another 60 health, and his ADC got those shields and heals, Oh and his passive is another 50 shield. Don't forget over heal which gave his adc an additional 150 shield. All because he pressed E, and the Q, and then E, none of which are difficult, and only one is a skill shot, and it spoint blank, and the animation doesn't self stun. So now, rakan ate all you damage, then healed some, then sheilded more, and hasn't even cast his W yet, which is ANOTHER DASH and a CC. Plus, after his W pops, his Q is back up to sheild and heal again.
Then his R, which unlike every other playmaker, is a starter not a follow up to his abilities. And not just any starter, its an AoE charm, that isn't a skill shot. He just runs into people, which isn't hard with 3 dashes, shureylias, righteous, a movement speed steroid and probably his flash, because hes never been caught, because of his 3 dashes. So after the 2 seconds of CC from his ult, he has more CC, and his team is all over you, because its not just any CC, its a charm that you walk back towards him because of. Leona, Thresh, Blitz, Alistar all have ults that reward them landing their initial combo. Rakan doesnt have any combos, he has one ability that you cant miss and his Ult GUARANTEES THE HIT AND FOLLOW UP AND RANGE ON.
So, to review, Rakan has Heals, sheilds, more sheild, another sheild, mobility, more mobility, CC, no skill required to "combo" with him, no penalty for going in, no sustain problems, Large ratios, can always pursue his ratios unlike Blitzcrank because he doesn't need tank stats, more CC on his ult, A movement speed steroid, mobility, more mobility, and his ult garuntees his W.
For comparison, Morgana, another LCS teir support has the following A slow moving snare (not stun), a high mana cost aoe that applies not affects except some damage, a high mana cost sheild, that can block CC, but only for a little bit, and doesn't help against physical damage, and an ult that needs to channel and stay in range, and is way less reliable than Rakan.
How do you balance that? How do you make Rakan a viable champion? You can't just change numbers on him and make it work. He'll permanently have unplayable numbers, or be OP, because of how diverse his kit it. The point for counterplay doesn't exist, especially when his sheilds and heals make him a seiging and scaling god for a support so he can sit back in the lane. Hes ranged. The only way to fix him, is to give him a clearly defined set of strengths and weaknesses. Rakan isn't alone. PLenty of other champions have too much stuff going on. Instead of doubling down on anything, all his abilties seem like an answer to one another's weaknesses. Thats not internal synergy, thats OP, thats unbalancable.