Italiced notes are ones that I see as most important, ex. Parting Shot for Banette.
Pokemon: Banette
Type: Ghost
Old Stats: 64 / 115 / 65 / 83 / 63 / 65 (455 BST)
New Stats: 74 (+10) / 135 (+20) / 65 / 113 (+30) / 65 (+2) / 115 (+50) (565 BST)
Abilities: Frisk / Prankster / Sheer Force (HA)
New Moves: Parting Shot, Fire Punch, Ice Beam
Removed Moves: None
Justification/Niche: This is the new ultimate Scout, taking inspiration from current CAP-mon Kitsunoh. Its stats have been given quite a bit of an overhaul, with a +50 to Speed being the most major. Frisk alongside a very fast 115 base Speed allow Banette to quickly check for Z-Crystals, Focus Sashes, and the like, then switch via Parting Shot into a proper answer for the set that's in front of it. A better mixed movepool also helps Banette, with the addition of Fire Punch to deal with Steels that may wall its coverage otherwise and Ice Beam to contest with the modern-day Dragon kings. These two moves also gain a nice buff in the form of access to Sheer Force, allowing it to be a fast mixed offensive threat. Already in its moveset to benefit from this is Gunk Shot, which already was pretty good and now is even better. Prankster is also a possible ability, allowing you to Destiny Bond before Bullet Punches and Aqua Jets come to revenge kill Banette, as well as for priority Will-O-Wisp. However, besides Prankster Parting Shot, a scouting Banette has little use due to a lack of bulk to survive after using a status move.
Pokemon: Absol
Type: Ghost/Normal
Old Stats: 65 / 130 / 60 / 75 / 60 / 75 (465 BST)
New Stats: 75 (+10) / 145 (+15) / 80 (+20) / 75 / 80 (+20) / 103 (+28) (558 BST)
Abilities: Mold Breaker /
Adaptability / Magic Guard (HA)
New Moves: Extreme Speed, Close Combat, Roost
Removed Moves: None
Justification/Niche: While Ghost/Normals probably would be nicer if they were bulky in order to use that nice defensive typing, Absol throws this out the window in turn for using the common Normal move STAB that it has alongside its moveset. Ghost/Normal has very few resists, the only ones being Tyranitar and Bisharp (and Pokemon that share this typing), and new access to Close Combat fixes that issue. All three of its abilities are amazing, with Mold Breaker allowing it to more effectively deal with things like Solid Rock, Sturdy, and Disguise; Adaptability helps increase the power of its very potent STAB moves; and Magic Guard gives it an immunity to entry hazards as well as Toxic or Burn damage, among other things. Extreme Speed, though, is the major new toy; A base speed of 103 can tend to get outsped in a meta where Tapu Koko STILL exists, and Choice Scarf can be rampant, so Swords Dance Absol can afford to now run ExtremeSpeed as its sole Normal STAB, allowing it to spam to its heart's content one of, if not the best, priority move in the game. Roost is also added to give sets, if a player chooses, a bit more survivability, especially with the upped bulk that's now just under mediocre for nowadays standards.
Pokemon: Malamar
Type: Ghost/Psychic
Old Stats: 86 / 92 / 88 / 68 / 75 / 73 (482 BST)
New Stats: 116 (+30) / 112 (+20) / 108 (+20) / 58 (-10) / 105 (+30) / 53 (-20) (552 BST)
Abilities: Contrary /
Poison Heal / Filter (HA)
New Moves: Shadow Sneak, Close Combat,
Recover
Removed Moves: None
Justification/Niche: Welcome to your worst nightmare. I'd have gone with Hoopa's confined form, but my idea was sniped by Gojiratar... almost entirely. So, instead, we have Malamar, who gains practically nothing from this new typing besides 2 immunities and dying even harder to Ghost types. What it gains instead is the incredibly neato abilities in Poison Heal and Filter, one giving it an ability usually restricted to things like Gliscor and Balanced Hackmons, and an ability which... reduces the damage that moves that already OHKO would do to only a 2x overkill, rather than a 8000x overkill. Awesome. Close Combat also gives it a more interesting move to run over Superpower for tanky builds, especially good now with a much better stat set defensively of 116/108/105. Recover also fixes the only final problem Malamar has ever had, that being it has bad survivability without defenses up already.