First and foremost, lets start with the Pokémon:
Smeargle
![Smeargle](https://i.stack.imgur.com/IjI73.png)
Smeargle is a great all-round Pokémon, as it's the only one that learns Sketch. It will learn Sketch every 10 levels starting from level 1, meaning by level 31 it will have 4 moves. Sketch will permanently copy a move used in battle, meaning that Smeargle can learn almost any move.
Using Sketch
You can guarantee the move Smeargle gets when using Sketch by entering double battles such as the ones in Restaurant Le Nah. Send out both Smeargle and the Pokemon whos move you want to copy, get it to use the move you want, such as False Swipe, and using Sketch, 'attack' your partner.
So how do I build the ultimate Pokémon Catcher using Smeargle?
Summary
Smeargle @Metronome
- Ability: Technician
- Nature: Adamant
- EVs: Speed, Attack and HP
Spore
With 100% accuracy, Spore is the preferred sleep move, but it is a little harder to get access to in X & Y.
Foongus learns it at level 50 (Amoongus at 62). Otherwise you can get a Paras through Friend Safari or GTS, who will learn it at 22. Shroomish will learn it at level 45.
Nevertheless Sleep Powder is the other safe option. Butterfree will learn it on level 12. Nice and easy. Otherwise Hoppip/Skiploom on 16 and Oddish/Gloom on 17.
I listed Stun Spore as a tertiary option, as some people swear by Stun for catching. Again Butterfree on level 12, Hoppip/Skiploom on 14, or Oddish/Gloom on 16 are your best bets.
False Swipe
False Swipe should be fairly obvious. It will bring a Pokémon down to 1HP, and never kill it. Perfect for catching Pokémon. As it's a Normal move, Smeargle also gains a Same Type Attack Bonus (STAB) when using it, bringing it's power from 40 to 60 (or from 60 to 90 with the Technician ability, see below).
It's TM 54, which can be found in Professor Sycamore's Lab. Talk to a woman on the third floor - she will give it to you. Teach it to any of these Pokémon.
Otherwise, Scyther can be rarely found on Route 21 and will learn it at level 13. your other options are Axew, Karrablast, Cubone or Zangoose (levels 24,25,27 and 29 respectively).
Taunt / Ingrain / Mean Look / Gastro Acid
This slot is a little up to personal preference.
- Taunt will force a Pokemon to use offensive-only attacks, meaning they won't be Teleporting/Roaring/Whirlwinding or inflicting status (at least from pure status moves). However it only lasts 2-4 turns.
- Ingrain will prevent Roar/Whirlwind/Dragon Tail/Circle Throw from making Smeargle flee, and also restore a little health at the end of a turn. However it doesn't stop Teleporting, and it means that Smeargle cannot be switched out.
- Mean Look prevents the target from switching out or fleeing (including via Teleport). Useful for Pokémon such as Abra, however unlike earlier games there aren't a lot of Pokemon that flee on sight.
- Gastro Acid useful for when a pokemon has insomnia, which stops it from falling asleep. However by using gastro acid, you can bypass insomnia and make them sleep anyway.
As for the ease of getting these moves:
- Croagunk will learn Taunt on level 10, or Absol on level 17. Taunt is also, TM 12, and can be found in the back of Team Flare Cafe. Talk to the Team Flare guy in the room with the beds you can sleep and heal in. Here is a video showing the path to take (minor spoiler).
- Ingrain is learned by Foongus on level 18, Phantump/Trevenant will learn it on level 13, Snover/Abomasnow on level 31 and Ferroseed/Ferrothorn on level 35. There are others, but these are probably the easiest to get a hold of.
- Gastly learns Mean look at level 8. You could try taking a Haunter to the move relearner for the cost of a Heart Scale, or you could throw a female Haunter into daycare with a male Haunter or Litwick. You'll have a wee baby Gastly in no time. Other options are Jynx on level 25, or Zubat on level 34.
- Joltik learns gastro acid at level 23. You can find joltik on route 116 using the dexnav.
Soak
Soak is awesome. I'm sure some people who were reading about False Swipe and Mean Look were crying out "But they don't work on Ghost!"/"False Swipe isn't very effective against Rock!". Well I'm here to tell you. Soak changes the target Pokémon's type to Water.
Not only does this mean that False Swipe/Mean Look will hit Ghost (and Rock/Steel normally), but Spore/Sleep Powder can hit soaked Grass-types too.
And as an added bonus (man I sound like a salesman), the enemy Pokémon no longer gets STAB from it's typed moves (meaning Smeargle takes less damage).
However, getting access to it may be a little harder:
- Basculin (both forms) learn Soak at Level 32. They can be fished for on Routes 15, 16, and 21, as well as Laverre City and Couriway Town with a Good Rod or Super Rod.
- Alomomola gets Soak at Lv. 33 - Fish for them in Azure Bay with a Super Rod
- If you haven't unlocked the Good or Super Rod yet, Psyduck will learn it on level 36 and is probably your best bet.
- At the time, I threw a Psyduck in daycare, put on the TV, and rode in a circle around the Centre Tower in Lumiose City (Side note: good to know for breeding).
Ok, that's a good start, but what about Natures/Items/Abilities/IVs/EVs?
Items
Lucky Egg can be used for an XP boost whilst levelling up. Find it in the Hotel in Coumarine City (talk to a girl there).
Metronome can be used to boost the power of consecutive False swipes (10% each turn). Again, head to Coumarine City, and check the Monorail station.
Some people also recommend Silk Scarf, for the immediate 20% boost to False Swipe it brings. If you're running the Technician ability (see below) you should probably go with Metronome. Can you guess where Silk Scarf is? That's right, COUMARINE CITY. Talk to the old man in the house by the docks.
Ability
Own Tempo or Technician (Player's choice)
- Own Tempo will prevent confusion which can be useful,
- Technician will boost False Swipe's power by 1.5x (from 40 to 60) (Which is then boosted further by STAB)
This really comes down to personal preference. Having tested both, I have found that I prefer the power boost from Technician than the protection from confusion via Own Tempo.
Note: Smeargle's hidden Ability is Moody, but I don't think it's useful in this situation. Stick with Own Tempo or Technician.
Nature
Completely optional, but Jolly (-SpAtk, + Speed) or Adamant (-SpAtk, +Attack) are probably the best ones. Honestly you'll get away with anything though.
EVs
Come on, you're facing off against wild Pokémon, it doesn't really matter. If you feel like trying to beat your best times in Super Training, avoid Special Attack. Everything else is personal preference. I spread mine over Speed, Attack and HP, in that order.
IVs
Don't even bother.
Notes:
- Do note that Smeargle won't attempt to learn Sketch if it still already knows Sketch, so make sure you use it before leveling up!
- Pokemon with the abilities Vital Spirit, Insomnia or Overcoat cannot fall asleep, and therefore will stop Spore.
- Soak can be countered by Pokemon with Magic Coat/Magic Bounce.
- Soak also wont help Spore land on Grass Pokemon with Sap Sipper, and will be negated entirely by the abilities Storm Drain, Water Absorb or Dry Skin. some Pokemon that can have these abilities are Maractus, Lileep, Cacnea/Cacturne & Paras/Parasect.
- However As listed by Trent below, having another Pokemon with Gastro Acid/Simple Beam/Entrainment or Skill Swap would be a good counter to Pokemon with these abilities
Best Answer
Phew. Man. This isn't super well documented. Here's what I've got:
Location takes precedence over friendship: In the case that your Eevee reaches the correct friendship level while around say, the Mossy Rock, it will always attempt to become Leafeon over Umbreon/Espeon. See here.
Fairy Move takes precedence over friendship: In the case that your Eevee knows a fairy move, it will always attempt to become Sylveon over Umbreon/Espeon... as long as you also have the 2 Affection. Fairy Move without 2 Affection obviously results in no Sylveon. See here.
The problem is if you hit all criteria. Say you have an Eevee that hits the right friendship level around the Mossy Rock (or the Ice one) and it knows a fairy move (and has 2 Affection). The question is, what does it turn into?
Friendship is the weakest evolution criteria by far (everything trumps friendship). So it probably would be duked out between the Fairy type move and the location. Still, some people say that the process is randomized (this theory is not documented well) and some people say that the fairy move/2 Affection will take precedence.
This is just a guess based on looking at all the information I could find, but it looks like the Sylveon evolution has so much going into it that it would be easiest for the game to check this first. See the comments by Swaggie Mils and Distincct here. So, and this is just a guess, Sylveon probably would take precedence over location. We'd need to do a test with multiple Eevees.
EDIT: I realized that Swaggie Mils and Distincct say "everything needs to be maxxed out" but I'm pretty sure that this is a safety precaution (to be sure you get a Sylveon). It only needs two Pokemon Amie hearts and a Fairy move, according to Bulbapedia. Fullness is not actually an issue, although I supposed it's best to just max everything out if you're trying to be sure. Still, if you're missing any of the Sylveon evolution criteria, you can't turn into a Sylveon... so I'm assuming the game checks for the fairy move, and if there is a fairy move then the affection, else if no fairy move/not enough affection then the location, then the friendship level. But this is a guess and not well documented, based on what I could find. It would still need to be tested.