In other news, White Treehollow is really fun, despite basically being "wander around fighting people". It's just that minor puzzle aspect of clue gathering, and the fact that, while limited similar to competetive battles (no item bag - even out of battle), you still get the switch-out choice when you KO an opponent, you still get XP and pokedollars for winning, levels actually matter...
And just for my own memory (or lack thereof), though others can comment and offer advice, I'll plan out my All-X assault teams.
Several pokemon are just "there because I have them", and their moves are listed as "what they have", not "what I intend on them having".
Fire
-Nintetales (Drought; Solar Beam, Hypnosis, Flamethrower, Will-O-Wisp; Item: Leftovers) - this may take a long time to catch
-Arcanine (Intimidate; Flare Blitz, Thunder Fang, Morning Sun, Outrage; Item: King's Rock?)
-Darmanitan (Sheer Force; Earthquake, Flare Blitz, U-Turn, Superpower; Item: Life Orb)
-Emboar (Blaze; Wild Charge, Flame Charge, Superpower, Head Smash; Item: Shell Bell)
-Volcarona (Flame Body; Quiver Dance, Heatwave, Bug Buzz, Hurricane/Solarbeam; Item: ???)
-Chandelure (Flame Body; Minimise, Will-O-Wisp, Hex, Overheat)
-Flareon (Flash Fire; Scary Face, Lava Plume, Fire Fang, Wish)
One of these is getting cut. Probably Emboar or Flareon
Water
-Vaporeon (Water Absorb; Wish, Scald, Acid Armour, Ice Beam)
-GYARADOS (Intimidate; Earthquake, Dragon Dance, Waterfall, Stone Edge?)
-Floatzel (Swift Swim; Rain Dance, Waterfall, Crunch, Ice Fang; Item: Damp Rock)
-Lapras (Shell Armour; Ice Beam, Perish Song, Body Slam, Thunderbolt)
-Palkia (Pressure; Spacial Rend, Aura Sphere, Aqua Tail, Dragon Claw; Item: Lustrous Orb)
-Milotic (Marvel Scale; Recover, Dragon Tail, Scald, Ice Beam; Item: Leftovers)
Electric
-Electivire (Motor Drive; Wild Charge, Flamethrower, Ice Punch, Cross Chop; Expert Belt)
-Galvantula (Compoundeyes; Thunder, Bug Buzz, Energy Ball, Gastro Acid; Item: ?)
-Jolteon (Volt Absorb; Pin Missile, Thunderbolt, Volt Switch, Shadow Ball)
-Ampharos (Static; Thunder, Cotton Spore, Focus Blast, Signal Beam; Item: Wide Lens)
-Zebstrika (Motor Drive; Flame Charge, Double Kick, Pursuit, Wild Charge)
-Magnezone (Sturdy; Thunderbolt, Flash Cannon, Substitute, Reflect; Item: Air Balloon)
Flying
-Crobat (Inner Focus; Cross Poison, Brave Bird, U-Turn, Roost; Item: Black Sludge)
-Drifblim (Aftermath; Shadow Ball, Acrobatics, Substitute, Will-O-Wisp; Item: Leftovers)
-Dragonite (Multiscale if available; Roost, Dragon Dance, Outrage, ExtremeSpeed; Item: Lum Berry)
-Braviary (Defiant; Brave Bird, Return, U-Turn, Superpower; Item: Shell Bell)
-Sigilyph (Magiguard; Psycho Shift, Cosmic Power, Stored Power, Roost; Item: Flame Orb)
-Altaria (Natural Cure; Dragon Dance, Rest, Fire Blast, Earthquake; Item: Evasion Incense)
Grass
-Leafeon (Leaf Guard; Synthesis, Leaf Blade, Sunny Day, GrassWhistle; Item: Warm Rock)
-Lilligant (Chlorophyll; Teeter Dance, Quiver Dance, Sleep Powder, Petal Dance; Item: Lum Berry)
-Leavanny (Chlorophyll; X-Scissor, Swords Dance, Shadow Claw, Leaf Blade; Item: Scope Lens)
-Ferrothorn (Iron Barbs; Gyro-Ball, Spikes, Power Whip, Leech Seed; Item: Rocky Helmet)
-Whimsicott (Prankster; Leech Seed, Substitute, Stun Spore, Fake Tears; Item: Leftovers)
-Virizion (Justified; Swords Dance, Stone Edge, Leaf Blade, Close Combat; Item: Wide Lens)
Bug
-Vespiquen (Pressure; Substitute, Roost, Attack Order, Toxic; Item: Leftovers)
-Accelgor (Hydration; Spikes, Last Resort, Bug Buzz, Focus Blast; Item: Focus Sash)
-Shuckle (Sturdy; Toxic, Sandstorm, Stealth Rock, Rest; Item: Lum Berry)
-Ninjask (Speed Boost; Double Team, Swords Dance, Baton Pass, X-Scissor; Item: Silver Powder)
-Shedinja (Wonder Guard!; Confuse Ray, Will-O-Wisp, Shadow Sneak, X-Scissor; Item: Evasive Incense)
-Heracross (Guts; Swords Dance, Stone Edge, Megahorn, Close Combat; Item: Rocky Helmet) - must trade for this
*Can always replace someone with a transferred Scizor (Technician; U-Turn, Bullet Punch, Superpower, Swords Dance)
Ice
-Weavile (Pressure; Ice Punch, Low Kick, Night Slash, Swords Dance; Item: Focus Sash)
-Vaniluxe (Ice Body; Hail, Toxic, Autotomise, Ice Beam/Blizzard; Item: Cold Rock)
-Cryogonal (Levitate; SolarBeam, Recover, Confuse Ray, Ice Beam; Item: Rocky Helmet)
-Beartic (Swift Swim; Icicle Crash, Superpower, Stone Edge, Aqua Jet; Item: Leftovers)
-Cloyster (Skill Link; Icicle Spear, Smash Shell, Rock Blast, Razor Shell; Item: Shell Bell)
-Froslass (Snow Cloak; Spikes, Taunt, Ice Beam, Shadow Ball; Item: Evasive Incense)
Ground
-Steelix (Sturdy; Earthquake, Stealth Rock, Gyro Ball, Dragon Tail; Item: Rocky Helmet)
-Mamoswine (Snow Cloak; Hail, Ice Shard, Stealth Rock, Earthquake; Item: Cold Rock)
-Seismitoad (Swift Swim; Rain Dance, Sludge Wave, Surf, Earth Power; Item: Damp Rock)
-Gliscor (Poison Heal; Ice Fang, Protect, Earthquake, Substitute; Item: Toxic Orb)
-Camerupt (Magma Armour; Earth Power, Stealth Rock, Lava Plume, Rock Polish; Item: ???)
-GARCHOMP (Sand Veil; Earthquake, Crunch, Outrage, Sword Dance)
*Replace something with Flygon (Levitate: Outrage, Earthquake, Fire Punch, U-Turn; Item: ???)
Rock
-Archeops (Defeatist; Dragon Tail, Stone Edge, Earthquake, Acrobatics)
*Or Aerodactyl (Rock head; Stone Edge, Double-Edge, Earthquake, Aqua Tail)
-Tyranitar (Sand Stream; Earthquake, Stone Edge, Crunch, Stealth Rock)
-Rhyperior (Solid Rock; Drill Run, Megahorn, Stone Edge, Ice Punch; Item: Leftovers)
-Omastar (?; Shell Smash, Scald, Ice Beam, Spikes)
-Rampardos (Sheer Force; Thunderbolt, Zen Headbutt, Head Smash, Focus Blast; Item: Life Orb)
-Terrakion (Justified; Close Combat, Stone Edge, X-Scissor, Sacred Sword)
Normal
-Cinccino (Skill Link; Tail Slap, Tickle, Bullet Seed, Rock Blast)
-Togekiss (Serene Grace; Body Slam, Air Slash, Roost, Aura Sphere)
-Blissey (?; Softboiled, Aromatherapy, Flamethrower, Toxic; Item: Leftovers)
-Stoutland (Intimidate; Return, Superpower, Crunch, Wild Charge)
-Zangoose (Toxic Boost; Facade, Close Combat, Night Slash, Swords Dance; Item: Toxic Orb)
-Vigoroth (Vital Spirit; Bulk Up, Earthquake, Body Slam, Slack Off; Item: Eviolite)
*or Slaking (Truant; Earthquake, Nightslash, Return, Retaliate; Item: something that boosts damage - ideally Choice Band)
*Maybe transfer Arceus (Multitype; Swords Dance, ExtremeSpeed, Earthquake, Will-O-Wisp; Item: Silk Scarf)across?
Fighting
-Mien-Shao (Regenerator; Fake-Out, U-Turn, Hi Jump Kick, Stone Edge; Item: Shell Bell)
-Scrafty (Moxie; Crunch, Dragon Dance, Hi Jump Kick, Zen Headbutt)
-Lucario (Steadfast; Drain Punch, Swords Dance, Ice Punch, Earthquake)
-Cobalion (Justified; Swords Dance, Sacred Sword, Stone Edge, X-Scissor)
-Primeape (Defiant; Encore, Close Combat, U-Turn, Punishment)
-Conkeldurr (Sheer Force; Bulk Up, Fire Punch, Mach Punch, Ice Punch; Item: Life Orb)
Steel
-Excadrill (Sand Force; Rockslide, Swords Dance, Drill Rush, Earthquake)
-Mawile (Intimidate; Iron Head, Fake Tears, Flamethrower, Swords Dance)
-Bronzong (Levitate; Psychic, Stealth Rock, Gyro-Ball, Sandstorm; Item: Dry Rock)
-Escavalier (Swarm; Megahorn, Iron Head, Pursuit, Toxic)
-Skarmory (Sturdy; Spikes, Roost, Brave Bird, Whirlwind)
-Jirachi (Serene Grace; Doom Desire, Iron Head, Wish, Thunderbolt)
Dark
-Krookodile (Intimidate - try to get a Moxie one; Earthquake, Crunch, Stone Edge, Superpower)
-Hydreigon (Levitate; Dark Pulse, Dragon Pulse, Focus Blast, Flamethrower; Item: Expert Belt)
-Darkrai (Bad Dreams; Dark Void, Dark Pulse, Nasty Plot, Focus Blast)
-Absol (Super Luck; Night Slash, Psycho Cutter, Stone Edge, Sword Dance; Item: Scope Lens)
-Zoroark (Illusion; Nasty Plot, Night Daze, Focus Blast, Flamethrower)
-Bisharp (Inner Focus; Iron Head, Night Slash, Swords Dance, Brick Break)
Psychic
-Beheeyem (Synchro; Trick Room, Psychic, Thunderbolt, Nasty Plot)
-Espeon (Synchro; Calm Mind, Stored Power, Baton Pass, Grass Knot)
-Metagross (Clear Body; Meteor Mash, Zen Headbutt, Bullet Punch, Thunder Punch)
-Gardevoir (Telepathy; Psychic, Focus Blast, Shadow Ball, Calm Mind)
-Latias (Levitate; Dragon Pulse, Recover, Psyshock, Substitute)
-Azelf (Levitate; Nasty Plot, Psychic, Thunderbolt, Flamethrower)
Ghost
-Coffin (Mummy; Will-O-Wisp, Hex, Haze, Rest; Item: Leftovers)
-Jellicent (Cursed Body; Toxic, Scald, Ice Beam, Recover)
-Golurk (Iron Fist; Substitute, Focus Punch, Shadow Punch, Earthquake)
-Sableye (Prankster; Taunt, Recover, Foul Play, Swagger)
*Or Spiritomb (Infiltrate; Pain Split, Nasty Plot, Dark Pulse, Smokescreen)
-Mismagius (Levitate; Pain Split, Nasty Plot, Shadow Ball, Thunderbolt)
-Giratina (Pressure; Rest, Sleep Talk, Outrage, Aura Sphere)
*Or Giratina-O (Levitate: Aura Sphere, Shadow Ball, Shadow Sneak, Dragon Pulse)
*Could always bring in a Gengar (Levitate; Focus Blast, Shadow Ball, Disable, Substitute)
Dragon
-Haxorus (Rivalry; Swords Dance, Shadow Claw, Superpower, Outrage)
-Druddigon (Rough Skin; Dragon Tail, Night Slash, Dragon Claw, ?)
-White Kyurem (Turboblaze; ?, ?, ?, ?)
-Zekrom (Terravolt; ?, ?, ?, ?)
-Dialga (Pressure; Aura Sphere, Flash Cannon, Dragon Claw, Sandstorm?)
Poison
-Scolipede (Poison Point; Megahorn, Venoshock, Toxic Spikes, Rockslide)
-Roserade (Natural Cure; GrassWhistle, Sludge Bomb, Giga Drain, Leech Seed)
-Garbodor (Weak Armour; Gunk Shot, Spikes, Drain Punch, Seed Bomb)
-Weezing (Levitate; Flamethrower, Sludge Bomb, Pain Split, Clear Smog; Item: Black Sludge)
-Toxicroak (Anticipation; Swords Dance, Cross Chop, Drain Punch, Ice Punch or Nasty Plot, Vac-Wave, Sludge Wave, Dark Pulse)
-Drapion (?; Earthquake, Whirlwind, Crunch, Pursuit)