Credit goes to YEYP.

Ampharos became a diaper for either not paying or chose the secret payment from the contract.

Name: Mercury Quicksilver
Nickname: Padded Pokehunter
Occupation: Mercenary/Bodyguard
Personality: Stern when battling/Teasing when having fun.
Identifiable: A regular Lugia, but slighty bigger and always wears either a regular diaper, or his personal diaper Kimo (http://www.furaffinity.net/view/21086658/) Thanks JamesG
Likes: Battling, Drinking, Diaper, and Diaper TF victims.
Dislikes: When clients not pay or try to hide from him.

Move Details:
Hydro Pump- Traditional Water Attack
Extrasensory and Psychoshock- Traditional Psychic Attacks.
Diaper Breathe: Exhales a massive breathe that varies on foes condition. He can also use this attack to refresh a dirty diaper into a clean one, if used on clean diaper it gets puffier, unfortunately the victim still feels and tastes the aftermath. (Victim is unaffected if at full Health, Diapercritter if banged up, Diaper if defeated.)
Secret Attack: Diaper Fusion- Fuses a victim to a diaper and they become a diaper. (He only uses this if they're gravely wounded)

Passive Skills:
Mind Reader- Able to read minds of Clients. (He only uses this to client tries to hide on payment.)
Telekenetic Plane- Able to communicate with Pampaku on an separate plane of exsistence. (He picked this up after constantly being around Pampakus waist.)

Contract and Payment:
Mercenary- Paid to fight or find rare items.
Bodyguard- Will guard and look after you.
Padded Punishment- Will work for free, on the condition you be his diaper for a couple of weeks. (He never tells his clients the details on this job, he finds shocked diapers fun.)
Good Side to it: He wears you until you're so full he can't fly. If he takes the diaper off he'll either refresh the diaper and keep for later or leaves them on their own. (The more they're used, the longer it takes, after they're clean, they'll be a diapercritter forever.)
Payment- He takes Money or Simple White diapers. (You can pay him at a later date, at the cost of doing something embarrasing for his entertainment. However, you only get 1 week, if you're still behind, you become his diaper for his collection."
Backstory:
This Lugia was once BFFs with Pampaku, they bonded real well over their love of diapers and transforming others into diapers thus having the nickname "Padded Pokehunter" which he takes pride in. Pampaku trained Mercury in various diaper moves, however Pampaku has it mastered and can make his enemies permanent diapers, where as Mercury can only temporarily make them diapers.
While flying about he saw a Typhlosion named Typhoon being picked by a herd of Ursaring. He saved Typhoon by turning the Ursaring into diapers and gave them to Typhoon. Unaware to Merc, Typhoon looked up to Merc as a hero, Merc decided to take up Mercenary work, because he loves battling and is always up for a challenge. He also finds clients fun since if they try anything, or not entertaining enough, he gets a nice fresh pamp out of it.
Pampaku was annoyed at Merc for turning victims into diapers for money instead of fun, so they had a battles that lasted for several days. In the end of the battles Pampaku won and Merc was constantly around Pampakus waist and taunting him. They became bitter rivals, but they usually make a deal with each other, Pampaku will send Merc to a random universe for either a cut of profits, 6 packs of diapers, or give diaperfied victim as payment.
Merc can be found at various Milk Bars, Juice Bars, and Gambling Houses. He can be identified as a big Lugia in a diaper with the distinct laugh "Lululu" he can tackle any job given at the right price. He'll also accept later payment, but he charges interest.
If there's a contract outside of the Pokemon world, he'll have to chat with Pampaku which he's not fond of. The longer you hire him, the more you pay. He read about a character named Yojimbo and decided to charge money per battle and attack. As much as enjoys ordinary diapers, he finds wearing victims fun since he can tease and taunt them. When tired, he'll find either an abandoned cabin or a dark forest to sleep. Despite his tough exterior, he's also be giant baby since he sleeps in a diaper, with a plushie and pacifier.
If really enjoys embarrasing his clients, by either forcing them into baby clothes and dancing around for him, or turning his clients friends/enemies into puffy diaper so that they have to waddle and talk with baby talk. Not paying, swindling, or trying to hide will result in the contract being broken and the clients will be either wrapped around his waist, saved for later in his diaper bag, or gives them to Pampaku. Since Merc is a drinker and glutton, the many diapers go crazy when they're used, even when they return as diapercritters they stil hire him since being wrapped aound a legendary is better than a diapercritter battling, another reason is Pampaku loves eating diapercritters.
If multiple people hire him, he gambles with them so he's not overwhelmed, You can confident and gamble him, or just walk away to avoid becoming a diaper (This rarely happens since clients would rather take the risk if it means being protected by a legendary). If you can't afford his contracts, you can get a discount if you can either beat him in gambling or be the only survivor to not be wrapped around his waist. If you won't pay him even when beating him in gambling or try to haggle him, he'll turn you into a diaper. He enjoys Poker, because he has a tough to read poker face. Hiring him means your also on duty with changing his diaper until the contract is finished. If the diaper is abandoned or Pampaku finds it distasteful, they slowly and automatically refresh themselves until they're a diapercritter.
Since he was friends with Pampaku, he took up saying some of his taunts, and he enjoys the thoughts he has, such as "how thick should this victim be" "This will be a fun and embarrasing diaper print." He also really likes th embarrass his victims by either rubbing their padded faces or slapping his crinkly butt since they can feel it and they blush when felt, since he sleeps in diapers, he never wakes up for bathroom breaks. Plus he likes how swollen his diapers get. As much as loves using diapers, he will bathe everytime he uses a couple of diapers and occasionally bathes in lakes, springs, or waterfalls, after all bars and gambling houses won't allow smelly pokemon and he does have class despite his personality. As much as he loves turning others into diapers, he won't do it to casino workers and bartenders. (Can't serve him if they have no fingers.)
Since he was wrapped around Pampakus waist countless times, he picked up some of Pampakus traits such as mentally talking to him on an Etheral Plane of Excistence, he honed his mental skills so well, he can telepathically read the thoughts of his diaper victims, though he mostly taunts and insults them. If you pay him on time and with the exact amount, he may give you diaper victim either random or choice, if they're worn, they can also telepathically speak to the victim. (Pampaku taught him how to do that before their fight.) He's also a glutton and loves to eat, and also has a high metabolism, even if he's fat, all of that will go to his diaper when used and he's back to average waist, belly, and thigh size.
He does enjoy music, he enjoys female singers with angelic voices. It gives him,a hypnotized loving gaze, it also helps calms him down and helps him sleep. When wakes up from sleep or nap, he listens to some metal that motivates him to fight, he finds country music disgusting. A client can also break a contract if the client pays him to steal or go after a character that's taboo. He also secretly likes dancing to pop music since he likes to work out. Not too big into sissy stuff, but he does enjoy miniskirts to show off his butt. He also does love bows and ribbons to put on his head (He thinks it makes him look cute.) Although he does enjoy wearing a pink vest with the initials PH (Padded Hunter) on the back.
When not on the job or wants some fun he'll mess around with Kimo as his personal plaything. Kimo is a shapeshifter so he can shapeshift, for Meecury he's either a diaper pail for Mercurys diapers to eat. (no tf victims.) A diapercritter when the breathe wears off, or serves as Mercurys Personal diaper. Mercury will often double with wearing Kimo and a victim/client, or diaperstuffs them. Since Kimos also a thief he's constantly running from the law, he wanted to protection so he decided to enter lifetime contract with Merc, on the condition Kimo follows and obeys all his rules, and policies.

Mercury Quicksilver belongs to me.
Lugia and Ampharos belong to Game Freak.