Because Im bored I thought I'd have a bit of fun and flesh out your idea (it seems cool!)
Champ name: Robutt (Just messing but that name works for now).
Electric Boost(Passive): Movement speed is increased while near electrified targets.
Pretty self explanatory. Robutt throws out a passive that electrifies targets. Maybe a 3/5/10% bonus movement speed by tiers.
Tesla Shock(Q): Sends out a projectile ball of electricity that does small amounts of damage to all enemies around it. If the ball strikes an enemy champion it deals large amounts of damage to all enemies around them and electrifies them.
Think a ball of lightning moving a bit slower then Morganna's Q, if it hits a champion it explodes electrifying the target and everyone around him and deal additional damage.
Absorb Energy(W): Target champion is snared for .5/1/1.5 seconds and if the enemy champion is electrified Robutt gains a temporary shield.
*Similar to Viktor's shield the animation for this would look similar to the drain from Blade of the Ruined King and grant Robutt a small shield. I dont want to tie any numbers to it at the moment.
Electrify(E): Robutt gains additional attack speed and his auto attacks electrify the target for the next 3 auto attacks.
Three very quick auto attacks, hard to micro manage because of the high attack speed, electrifies targets.
Data Metamorphose(R): Robutt gains the ability to use the target electrified champion's ultimate at no cost for the next 3 seconds.
In order to keep this from being ridiculously overpowered in the right hands I made it so that the target has to be electrified and he can only use the ultimate 3 seconds after stealing it. The way I imagine that animation is that he targets a champion and when he uses the ultimate the enemy champion kind of flashes on the screen on top of him doing the ultimate... think chrono trigger after you beat a boss and its kind of fading in and out. Thats what Im shooting for.
Special Interactions
Viktor: Beep Boop, Orders master?
Blitzcrank: Logically speaking, there can be only one.
Blitzcrank: Ha Ha Ha. (blitzcrank laugh) I do it better.
Orianna: Oh baby.
Ultimate's that are hard to copy, and solutions to copying them.
Orianna: No ball, he just ults on top of himself.
Elise: I seriously have no idea...
Jayce: Still no idea. Maybe he just cant copy these.
Corki: He gains 3 missiles he can fire.
Ahri: He can dash 3 times, her image does the dash ontop of him (like I described before) every time.
If you can think of any other ultimates that might be hard let me know..
Position:
I think he would be played as a kind of AP brusier top or an AP mage mid.
The problem as having him as a mid is I think most of his abilities should have a short-ish range so he would be pretty easy jump on if he is squishy. Not to mention his auto attacks are his only 100% reliable way to electrify as his Q is slow moving.
Special skins:
Definitely Not Blitzcrank knock off
Terminator Skin
Nutcracker Dancer Skin (making fun of ori!)
More stuff
If you've read this far then thanks for reading, I just get bored and write these up for fun. If you have any suggestions or anything to add let me know. Thanks!
(the rest of story,,, depends on riot team)
, After 5
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so when his half body is 
