Kabutops Crest: speed increase and sturdy ability
Hypno Crest: sp atk and atk increase with bad dreams or dream eater like ability (maybe add hypnosis 100% accuracy?)
Seaking Crest: speed increase and sap sipper ability
Snorlax Crest: can hit ghost types with normal moves and have leftover like healing
Tauros Crest: When using must recharge move like Giga impact or hyper beam, if opponent mon is knocked out, no need to recharge and tough claw (horn) ability.
Flareon Crest burned and speed increase and/or make guts like ability but increases sp atk instead of atk while scaling sp atk with atk.
Lapras Crest: snow warning and increase speed in hail. (maybe include electric stab bonus?)
Rapidash Crest: Drought and increase speed, accuracy, and evasion in sun.
Parasect Crest: Normal moves can hit ghost types and increases catch rate of other pokemon. spore always hits ignoring type
Golduck Crest: psychic stab and simple ability
Noctowl Crest: increase def and sp def and have psychic stab
Dunsparce Crest: increase all base stats and when increasing and/or decreasing stats, instead of increasing/decreasing by 1 stage make it 2.
Xatu Crest: increase sp atk and upon switching in use future sight. (maybe add ability to hit dark types?)
Girafarig Crest: increase stab multiplier and speed. (maybe gain dark type for the tail?)
Sudowoodo Crest: increase hp and sp def and have grass stab (maybe with iron fist?)
Lanturn Crest: Priority pivot move and has both volt and water absorb. after using electric move gain charge eff (maybe throw in a sp atk, sp def, and speed increase?)
Qwilfish Crest: Upon switching in set up toxic spikes, upon taking physical dmg opponent take some dmg (like rocky helmet, and moves can flinch and/or increase flinch chance
Corsola Crest: increase all base stats and update art of corsola with knife. the knife increases threat level
Shuckle Crest: increase hp and upon switch in set up sticky web with oblivious ability
Sunflora Crest: Drought and increase speed. Petal moves do increased damage. Immunity to fire.
Octillery Crest: Increase accuracy and special moves hit twice like parental bond.
Ampharos: cotton guard upon switch (maybe gain volt absorb or lightning rod?)
Swellow Crest: burns and moves hit twice like parental bond
Slaking Crest: Can counter some dmg back and take less dmg during truant turn
Armaldo Crest: have water stab. increase speed or give analytic like ability
Delcatty Crest: can hit ghost type and normal moves can be used as fairy if super effective and will become stab. increase speed and atk.
Flygon Crest: make stats like a pseudo legendary and increase evasion and accuracy in sand. sound moves increase dmg.
Walrein Crest: takes less dmg from super effect moves
Swalot Crest: Draining moves deal more damage and heals more and stockpile 1 upon switch in.
Tropius Crest: Increase sp atk, speed, and accuracy with drought
Torkoal Crest: increase fire power and sturdy ability
Kecleon Crest: upon taking dmg change type to make it not effect (like taking fire dmg turns into water)
Cacturne Crest: Needle moves do more dmg and increase speed in sun and rain. lose hp in hail
Luxray: strong jaw and reckless and gain dark type or dark move stab with increase speed.
Vespiquen Crest: Order moves have priority and effects are increased and takes less dmg
Chatot Crest: priority sound moves and throat spray like ability.
Lumineon Crest: Drizzle and leftovers like ability
Drifblim Crest: burns and increase speed with life orb like ability.
Kriketune Crest: Upon switching confuse or make opponent fall asleep. tough claw like ability and speed increase
Magmortor Crest: Speed = Special attack. immune to water
Throh Crest: first move is priority and increased dmg.
Braviary Crest: gains gale wings. normal dmg to rock and steel.
Zebstrika Crest: Switch attack and special attack. after using electric moves gain charge eff.
Sigilyph Crest: Gain simple and resist rock and dark
Avalugg Crest: Immune to fire and solid rock ability. increase sp def in hail
Furfrou Crest: immune to certain type based on haircut and do more damage to certain type with haircut.
Chestnaught Crest: upon switch leech seed and rough skin
Delphox Crest: redirects status moves or nullifies them. (kinda like counter spell?)
Greninja Crest: Water shuriken hits 5 times and dark moves have flinch chance
Mudsdale Crest: def and leftovers
Golisopod Crest: sets up spikes when emergency exit and increase dmg to priority moves
Mimikyu Crest: when disguise is gone set up sub and speed increase
Silvally Crest: base stats like legendary and adaptability.
Corviknight Crest: Dark stab and leftover like ability
Falinks Crest: Moves hit up to 3 times