Reserving a pokemon for all 3 of you. Will edit later.
EDIT:
loudkirbyking, you get Highwind the Wingull (MUST be caught as a Wingull). Highwind, like Cid Highwind from Final Fantasy, loves his spear and loves to fly. So, he must know Quick Attack and Wing Attack ASAP, and use them to solo Roxanne at no higher than level 18. To evolve, because Cid Highwind just throws himself into any attack, must solo 75 electric types, at no higher than 5 levels above each, including at least 2 of Wattson's pokemon. Also, he wants to fly to the ends of the earth, so once he learns a flying type attack, must always keep a flying type move, following all other restrictions at the same time. On his way to the ends of the earth, Highwind runs into a lot of flying types, and so Highwind must solo 250 flying types, and Wiona as a Pelliper. If Highwind ever faints, he thinks he got placed back in the center of the earth, and so must solo 250 more flying types, and 50 more trainer-owned electric types for every time Highwind has fainted. That should be hard enough, so just one more thing: solo 1 member of the E4, and solo Steven's MP without SE moves.
ReshiramBlackZekromWhite, you're lucky. Since luigi gave you such an annoyingly hard challange, I'll give you an MVP. You get Hup! the Lillipup. Hup has an eternal case of the hiccups, and so must know Work Up and use it against every gym leader Hup solos. Hup must also have the ability Pickup, and pick up 10 items to meet one evolution condition. The only other condition is that Hup must solo both Cilan/Cress/Chili's Lilipup and Lenora's Herdier. After Hup evolves, all restrictions beside the pickup one remain, and to evolve, Hup must solo Clay to evolve again, only this time without SE moves. When Hup becomes a Stoutland, Hup only has to keep Work Up. Finally, have Hup solo either Marshal or Grimsley, and land the final blow on Ghestis's last pokemon.
LafondaOnFire, you get a tribute to my first flying type, the one I am most sentimentally connected to. You get Cindy the Tailow. Cindy always knew Endeavor, and so must know Endeavor once she learns it, and must use it to get 10 pokemon to 20 or less HP. Cindy was always extremely loyal, and so must always be in your party. She also loved flying types, and so must solo 50 flying types and Wiona. She evolved after Flannery, so Cindy cannot evolve until you have 4 gym badges, and Cindy has soloed 15 electric types owned by trainers, to show her reliability. All the rest is up to you.
Good luck to the 3 of you!!