In Runeterra, wandering entertainers can make a fair living on small towns and villages, at least the ones that do not attempt on their lives. The most famous entertainer of these drifting groups is Burton, the Copycat Magician, a mysterious man with as much flourish as his skill in magic. His namesake comes from his ability to copy any spell used against him perfectly, though not always with the same power or speed as the original. Burton tells numerous stories about how he obtained his skills, though only a few are to be believed. What is certain is that Burton could take on any mage against him, with few opponents able to match his magical prowess.
"My secret? Magician's secret, I'm afraid."― Burton
My first major inspiration for Burton was Rubick from Dota 2, mainly his ultimate where he copies the last spell used by the target champion. I kept it, but actually nerfed it a bit by adding more cooldown time and mana cost due to the massive effect it could have. This one ability makes him extremely versatile, able to copy game-changing moves like Amumu or Trydamere's ults as long as he isn't murdered by either before using his ult.
After that, I designed him as a hybrid AD/AP build like Jax, unlike TF, whose more of a hybrid AS/on-hit build. This fits into his ultimate as well as his regular abilities, as building straight AD or AP would make stealing something like a Malzahar ult or Darius ult ineffective if the opposing stat is invested in.
Obviously, certain abilities simply cannot be stolen due to their interactions with their champions. All of Orianna's abilities cannot be stolen, nor can Kalista's ultimate. In general, Burton's ultimate does not steal passives or toggle abilities. Objectively, there are obvioulsy abilities that are more worth stealing than others (Poppy's ult is significantly more useful than her Q), so caution needs to be taken.
"Let's have a magic show."
"Alakazam!" "I make you disappear!" "Loud gibberish!" "Voila!" "Abracadabra!"
"Shame I can't teleport...yet" "Always wandering..." "You know, walking seems less romantic here."
*Burton extracts a variety of objects from his hat* "Pigeon, pigeon, rabbit, dead rabbit, pigeon rabbit, boot, electric bill, wallet..."
"I need a volunteer for my next trick. It involves a lot of saw blades."
Stealing an Aatrox's Q
"Must be easier to do with wings."
Stealing an Ahri's E
"Well the ladies always said I was charming."
Stealing an Akali's W
"Now you see me..."
Stealing an Alistar's ultimate
"Stealing Alistar's ultimate fills you with WILLPOWER."
Stealing an Amumu's ultimate
"This is...not going to go well for them."
Stealing an Anivia's W
"I'm probably going to misuse this, but whatever."
Stealing an Annie's ultimate
"Hey Annie, I found him!"
Stealing an Ashe's ultimate
"I believe this belongs to you ma'am."
Stealing an Azir's ultimate
"Oh such lovely assistants!"
Stealing a Bard's ultimate
Stealing a Blitzcrank's Q
"No, I grab YOU."
Stealing a Brand's abilities
"I do so love fire magic."
Stealing a Braum's ultimate
"So you just punch the ground really hard? Interesting."
Stealing a Caitlyn's ultimate
"Impressive marksmanship, sheriff."
Stealing a Cassiopeia's ultimate
"So it isn't the face that causes the stun...I have a lot of jokes I need to take back."
Stealing a Cho'gath's ultimate
"Well I'm not too picky about my food..."
Stealing a Corki's abilities
"Pew, pew, pew!"
Stealing a Darius's ultimate
"No, I dunk YOU."
Stealing a Diana's Q
"By the light of...the moon, isn't it?"
Stealing a Dr. Mundo's ultimate
"Holy cow, do you ever get injured?"
Stealing a Draven's abilities
"So it's just a couple really big axes...not that impressive really."
Stealing an Ekko's ultimate
"Now this is real interesting magic, young man. Bravo to you."
Stealing an Elise's E in spider form
"I don't have to spit this out of my buttocks, do I?"
Stealing an Evelynn's ultimate
"Now this will be fun to use."
Stealing an Ezreal's ultimate
"A really big disc of doom...why haven't I made that?"
Stealing a Fiddlestick's ultimate
"CAW! Oh no, it's affecting m-CAW!"
Stealing a Fiora's ultimate
"The wand is stronger than the sword, I hope."
Stealing a Fizz's ultimate
"Now I pull sharks out of hats. And they saw you can't teach an old dog new tricks."
Stealing a Galio's ultimate
"Oh yes, because I love when people beat me into a stain."
Stealing a Gangplank's ultimate
"Yo ho, I don't know the rest."
Stealing a Garen's ultimate
"I feel an intense need to shout my country of origin."
Stealing a Gnar's ultimate in Mega Gnar form
"...I really hope I don't break my arms doing this."
Stealing a Gragas's ultimate
"I'm pretty sure this drink would remove paint off buildings."
Stealing a Graves's ultimate
"You have an amazing shotgun, my handsome assistant."
Stealing a Hecarim's ultimate
"You really are scary, you know?"
Stealing a Heimerdinger's ultimate
"...I did not want to steal this."
Stealing an Illaoi's ultimate
"Never was much for tentacles..."
Stealing an Irelia's ultimate
"I see we both think the same way, Ionian woman. Hybrids are the best."
Stealing a Janna's ultimate
"Wind magic is...interesting."
Stealing a Jarvan's ultimate
"I will use this to aid my team, I promise."
Stealing a Jax's E
"Time to swing wildly in the air and dodge everything."
Stealing a Jayce's Q in Cannon form
Stealing a Jinx's ultimate
"No, goodbye to you!"
Stealing a Kalista's W
"Scout ahead, spooky ghost!"
Stealing a Karma's Mantra-empowered abilities
"Yep, I can steal that too."
Stealing a Karthus's ultimate
"Oh boy, you all are going to die."
Stealing a Kassadin's ultimate
"Wow, I can only use this once."
Stealing a Katarina's ultimate
"Well I already have the knives..."
Stealing a Kayle's ultimate
"Now this is a great spell."
Stealing a Kennen's ultimate
"Sparks are flying!"
Stealing a Kha'Zix's ultimate
"Such an interesting creature with such an interesting creature..."
Stealing a Kindred's ultimate
"Mastery of life and death...what are you two?"
Stealing a Kog'Maw's ultimate
"A shame it only works once."
Stealing a LeBlanc's abilities
"Huh, no silence? My memory must be off."
Stealing a Lee Sin's ultimate
"Well my knees aren't so great, but I can try..."
Stealing a Leona's ultimate
"The sun has such power? Good to know."
Stealing a Lissandra's ultimate
"Time to give the...cold shoulder. Get it?"
Stealing a Lucian's ultimate
"Where did you buy your guns, because I'd love a pair?"
Stealing a Lulu's ultimate
"Up we go, indeed."
Stealing a Lux's ultimate
"Time for me to be the one laughing."
Stealing a Malphite's ultimate
"Okay, so I just run at them, right?"
Stealing a Malzahar's ultimate
"This is not going to be fun for you."
Stealing a Maokai's E
"Ah, he's so cute! The little sprout, I mean."
Stealing a Master Yi's ultimate
"I love jogging!"
Stealing a Miss Fortune's ultimate
"A shame I can't copy your...other assets."
Stealing a Mordekaiser's ultimate
"Never one for slavery, but to each their own..."
Stealing a Morgana's ultimate
"I got these chains on me..."
Stealing a Nami's ultimate
"Water...who knew it held such power?"
Stealing a Nasus's Q
"This...was not a good idea."
Stealing a Nautilus's ultimate
Stealing a Nidalee's Q
"I better not waste this."
Stealing a Nocturne's ultimate
Stealing a Nunu's ultimate
"Just painting a big sign over my head..."
Stealing an Olaf's ultimate
"Okay, I need this permanently."
Stealing a Pantheon's ultimate
"Jump really, really hard, right?"
Stealing a Poppy's ultimate
"Good think I don't actually HOLD the hammer, right?"
Stealing a Quinn's ultimate
"Does this work with doves?"
Stealing a Rammus's abilities
Stealing a Rek'Sai's ultimate
Stealing a Renekton's W
"If only I took your big blade with it."
Stealing a Rengar's ultimate
"Let's see how you like surprise murder."
Stealing a Riven's ultimate
Stealing a Rumble's ultimate
"Here comes the Equalizer!"
Stealing a Ryze's ultimate
"Okay, this is a good steal."
Stealing a Sejuani's ultimate
"Time to throw these large...chain...thingies..."
Stealing a Shaco's ultimate
"And now I saw myself in half!"
Stealing a Shen's ultimate
"I will probably be there in time to save you, teammates!"
Stealing a Shyvana's E
"Rawr, I'm a dragon!"
Stealing a Singed's ultimate
"This stuff tastes...disgusting."
Stealing a Sion's ultimate
"So how do I stop, exactly?"
Stealing a Sivir's ultimate
"Apparently I can start a jogging club now."
Stealing a Skarner's ultimate
"Good thing I can conjure a tail, or this would be really awkward."
Stealing a Sona's ultimate
"This is going to be fun."
Stealing a Soraka's ultimate
"Is yelling "live" necessary?"
Stealing a Swain's ultimate
"The bird is the...I won't say it!"
Stealing a Syndra's Q
"...this is underwhelming."
Stealing a Tahm Kench's ultimate
"Now just hop into my hat and it'll work...probably..."
Stealing a Talon's ultimate
"Thank you for your poor decision."
Stealing a Taric's ultimate
"Gems aren't that outrageous."
Stealing a Teemo's ultimate
"I'm not a fan of mushrooms, thanks."
Stealing a Thresh's ultimate
"Why does this box not have a lid?"
Stealing a Tristana's ultimate
"Don't make me use my finger gun!"
Stealing a Trundle's E
"I'll just stick this...there!"
Stealing a Tryndamere's ultimate
"Time to get really, really, angry."
Stealing a Twisted Fate's ultimate
"Think I can borrow the magic cards some time, TF? I got a killer card trick."
Stealing a Twitch's Q
"...this seems redundant."
Stealing an Udyr's E
"Bears are bad news after all."
Stealing an Urgot's ultimate
"The old switcheroo, huh? Nice trick."
Stealing a Varus's ultimate
"Yet again with these tentacle things...weird country we live in."
Stealing a Vayne's E
"Watch out for walls boys and girls."
Stealing a Veigar's ultimate
"Oh boy, oh boy! This is the best day ever!"
Stealing a Vel'Koz's ultimate
"Do two eyes make it stronger?"
Stealing a Vi's ultimate
"Well my fists are not metal-clad, but I shall try my best."
Stealing a Viktor's E
"Doom laser! What, it isn't called that?"
Stealing a Vladimir's ultimate
"Seems weak, but it packs a massive punch."
Stealing a Volibear's Q
Stealing a Warwick's ultimate
"Imma eat you!"
Stealing a Wukong's ultimate
"Does this stick have a size limit?"
Stealing a Xerath's ultimate
"How exactly did I get this close to you anyway?"
Stealing a Xin Zhao's ultimate
Stealing a Yasuo's ultimate
"A real shame I don't have a knock-up..."
Stealing a Yorick's abilities
"...how do I use this again?"
Stealing a Zac's ultimate
"Boing! Boing! This is fun!"
Stealing a Zed's ultimate
"Only a fool fears shadows."
Stealing a Zigg's ultimate
"So the secret is gunpowder, right?"
Stealing a Zilean's ultimate
"Wow, my team is going to love me."
Stealing a Zyra's ultimate
"Rise, my...plants! Sounded more dramatic in my head."