[Champion Concept] Eisho, the Enlightened Monk
Turns out the Shurimans weren't the only ones who discovered the secrets of ascension.
BACKSTORY
Legends say that in the temples of Ionia a band of monks discovered the magics of ascending independently from the Shurimans, although they referred to the state as becoming "enlightened". However Instead of a grand ceremony where one ascended instantly, the monks would meditate for months or years in their temples that they built around ancient statues made of a mysterious metal that seemed produce sunlight from within. These statues were not as powerful as the mighty sun disks found in Shurima, however prolonged contact with them could endow the monks with minor powers; such as slower aging and increased agility/strength. Especially dedicated monks could even manage to harness some of the magical powers emanating from the statues, allowing them to have supernatural abilities, although the full effects varied from person to person.
Of course, with power comes those who wish to test it's limits. One monk, Eisho, wished to find the secrets behind the statues and test the limits of their power. Eisho believed that once these statues brought the Ionians great power and longevity, and that as they decayed so did the magical lands around them. He proposed to the masters of each temple to bring all the statues together, arguing that together the statues would likely grant a significantly greater effect, and perhaps they could make Ionia great again. However, the masters shot the idea down with haste; claiming that such an idea was far too dangerous and that no man would be able to withstand the combined power of the statues. Frustrated with their answer, Eisho decided that it was up to him to save his home from a slow decay. He stole the statues from each temple, hiding them in cave deep within Ionia's forests, and as he brought each statue together he could feel the energy in the cave growing, making him stronger (Which conveniently helped him steal more statues). Finally, after years evading those who wished to stop him, Eisho brought the last statue into the cave, completing a large circle of the idols. As he placed the statue down, Eisho immediately felt the ground beneath him begin to tremble. Excited that his decades of work was paying of, Eisho ran to the center of the circle; entranced by the power that had started to radiate throughout the cave. He was finally going to prove the masters wrong.
The masters were right. The energy produced by the statues could not be contained in Eisho's mortal body. As the cave began to crumble around him, Eisho began to crumble as if he was made of loosely fitted stones. The statues began glowing brighter and brighter until they began to explode sequentially, devastating the surrounding area. Yet when the rubble was finally cleared, no trace of Eisho could be found. Many say that he was simply destroyed by the power he couldn't control, his body crumbling to ash that blew away in the wind. Yet there are some who believe that Eisho wasn't killed, and instead the monk shed his body in exchange for one of pure magical energy. For thousands of years this was believed to be an old wives tale, as the very few who claimed to have glimpsed the shape of man made of a bizarre light could not prove what they saw.
However, with the recent news of an ancient Shuriman Ascended made of pure energy, wild speculation has once again risen that perhaps if a Shuriman slave could endure the effects of ascension, then so to could a trained Ionian monk. Strangely enough, this has coincided with an increase in strange lights and sounds being observed in many regions of Ionia. Villages and towns near the forest claim that they can occasionally see a streak of blue light in trees and hear a distorted voice whispering in the wind. One Noxian patrol even reported that during the invasion of Ionia they were overwhelmed by an "indescribable force". It would seem that the tension building in Runeterra has attracted the attention of previously dormant power.
Eisho deeply regrets his decision, and wishes to atone for the destruction he caused to the land of Ionia and the sun statues. He sees himself as an abomination but has yet to find a way to die. When the Noxians came to Ionia he was a key element in driving the forces away, although neither side were aware of him and the destruction of Noxian legions was assumed to be the work of one of the many other Ionian one man armies. When he heard of Xerath, a man who suffered the same fate as him; he was immediately intrigued. Initially he planned to discuss the condition with his fellow enlightened, but was horrified to learn that Xerath was using his power to build an army. Eisho believes it is his duty to put an end to Xerath's destruction, or die trying. Really a bit of a win-win for the guy.
TL;DR: Eisho Was an Ionian monk who underestimated the power of what was basically a bunch of small sun-disk statues. Now he is pure energy like Xerath and seems to be stirring into action after many years of doing nothing.
ACTUAL CHARACTER STUFF:
Eisho is an ascended Ionian monk. Unlike Xerath, he spent the millennia after his ascension training and studying his abilities. Because of this he has managed to restrict his energy into a form that resembles his previous self, and he has more control over his powers.
PASSIVE - ARCANE FISTS: Eisho is pure magic energy, he cannot do damage through physical means. Instead of dealing AD with auto attacks, he does 100% of his AP in magic damage.
Q - Arcane Combustion Engine: after a brief cast time Eisho fires a powerful blast of energy behind, propelling himself forwards at high speeds. Hitting someone with the backblast of the ability deals a large amount of damage, the dash deals damage and marks enemies hit.
W - Arcane Lightning: PASSIVE- Moving and attacking generates Energize stacks, up to 100. When fully Energized your next attack deals bonus magic damage that chains to nearby enemies. Attacking a marked target will detonate the mark and trigger the Energized effect.
E - Arcane Bomb: Eisho lobs a ball of energy that explodes at a target location, dealing damage and stunning in a small AoE. Enemies hit are also marked.
R - Arcane Implosion: Eisho lets his energy run free, briefly becoming untargetable as the energy explodes outwards dealing damage to enemies hit and marking them. After the energy hits it's maximum radius; Eisho quickly reshapes himself, dealing damage again and pulling enemy units towards the center slightly. The second part of Arcane Implosion also detonates marks on enemy champions.
MY EXPLANATION/BALANCE EXCUSES:
PASSIVE: Similar to Jhin, Eisho will be able to do more damage with his auto attacks than most champions. However I believe this would be balanced by the fact that he would not benefit from most attack speed items as he cannot critically strike (well he can it just does a bonus 200% of his 0 AD).
Q: I really enjoy this concept for an ability. It can be used as either his engage or disengage and you have to decide between getting the higher damage from the backblast but then moving out of range of your other abilities/aa's and committing to the fight/marking your target. I had another idea for the ability where it works like a Vi Q, ramping up in distance and backblast damage as you charge it. This would allow for a quick cast in close fights to get your mark on a target but also stay near them.
W: This is pretty much his main source of reliable damage. It's just statikk shiv but scales with his AP and can be procc'd from marking targets. if he marks multiple targets he can get a decent amount of chain damage by proccing all the marks.
E: This move I came up with to kind of highlight the similarities between Eisho and Xerath. It's the same concept of a stun-ball, but since Eisho has managed to control his power a bit more he has learned to lob the ball over minions in exchange for losing some range on the ability.
R: This is Eisho's big old teamfight move. The first bit of it is some decent AoE damage, but the second half is the important part. The enemy team needs to leave the AoE or else take the damage again + his W damage. If he manages to get a 5-man ult he can do some serious damage.
Alright, this is my first take at a champion design that I made when I was bored at 12am. Sorry about the long everything, I got more into this than I though I would. Please let me know what you think and whatnot. I'm pure garbage at drawing so no concept art but I'll describe my vision of the guy so maybe another interested individual can draw it for me.
DESCRIPTION:
Eisho: Blue Energy like Xerath, but contained to a more humanoid shape so that you can tell he's kind of monk-looking. A weird blue Lee Sin.
Q: a blast of blue energy behind him as he zooms forward in a straight line. Maybe some brief remnants of energy crackle on the ground that he covered.
W: Statikk Shiv but blue lightning. Marked enemies have a blue glow.
E: He just tosses a blue energy ball that explodes when it hits the ground.
R: Kind of like a Vlad W but with a large radius and it takes a small amount of time to spread out, also instead of a solid color it looks more like a field of electricity. Then it quickly reverts back into the his original form, sucking people in like a Diana E.
, 
or 
based on whether he has mana or not.
Note: Item order might vary based on game.
, even ignoring his ult, can usually 100-0 people with just his kit/build. Tank isn't really needed since the best kind of peel is for the enemy to already be dead. That is ludicrous on it's own, but this guy does entirely AoE damage. I'm not saying his kit is terrible, but it IS unbalancable. It's virtually impossible to give him enough damage to be viable without overtuning him and blowing up the high elo with this guy.