Hey apologies it's been an incredibly long while since the viability rankings was previously updated, but today we have an official update on the viability rankings based on new changes and discoveries made throughout 2025, fit to adjust accordingly to the modern state of the metagame. As always, feel free to look over these and discuss rankings. Always be civil and to not slander others over the ranks.
The viability rankings have been overhauled. There is no longer a Wonder Guard Viability Rankings in the format. It was deemed unnecessary after noticing teams, particularly hyper offense, being very well capable of having consistency even without any Wonder Guards within the team. Each Pokemon are ranked individually with all their possible abilities factored in. The abilities listed are three at most to shorten the list, but are not exclusively the abilities they may run in plenty of cases. Enjoy!
Viability Order: S to A-
S Rank
S

Chansey (Imposter, Innards Out)

Blissey (Imposter, Innards Out)
S-

Mewtwo-Mega-X (Huge Power, Magic Bounce, Magic Guard)

Kartana (Huge Power, Wonder Guard, Magic Guard)

Mewtwo-Mega-Y (Psychic Surge, No Guard, Protean)
A Rank
A+

Slaking (Huge Power, Harvest)

Gengar-Mega (Parental Bond, No Guard)

Zygarde-Complete (Prankster, Magic Bounce)
A Rank

Audino-Mega (Wonder Guard)

Groudon-Primal (Magic Bounce, Shadow Tag, Huge Power)

Regigigas (Huge Power)

Meloetta (Wonder Guard)
A- Rank

Arceus (Wonder Guard, Harvest)
Gyarados-Mega (Wonder Guard, Magic Guard, Shadow Tag)
Slowbro-Mega (Wonder Guard, Prankster, Fur Coat)

Celesteela (Wonder Guard, Prankster)

Ferrothorn (Wonder Guard)

Kyogre-Primal (Wonder Guard)
Rayquaza-Mega (Triage, Mold Breaker, Shadow Tag)
Alphabetical Order: B+ to E
B Rank
B+

Deoxys-Attack (Magic Guard, Huge Power, Psychic Surge)

Deoxys-Speed (No Guard, Mold Breaker)
Diancie-Mega (Pixilate, Magic Guard)

Ho-Oh (Wonder Guard, Prankster)

Hoopa-Unbound (Wonder Guard)
Lopunny-Mega (No Guard)

Muk-Alola (Wonder Guard, Mold Breaker)

Pheromosa (Huge Power, No Guard, Comatose)

Scizor-Mega (Wonder Guard)

Steelix-Mega (Prankster, Fur Coat, Magic Bounce)

Yveltal (Magic Bounce, Magic Guard, Harvest)
B

Aerodactyl-Mega (No Guard, Shadow Tag)

Doublade (Fur Coat, Magic Bounce, Sturdy)

Giratina-Origin (Innards Out, Harvest)
Greninja-Ash (Wonder Guard, No Guard, Comatose)

Lunala (Innards Out, No Guard, Adaptability)

Heatran (Wonder Guard)

Sableye-Mega (Wonder Guard)

Swampert-Mega (Wonder Guard)
Umbreon (Wonder Guard, Magic Bounce)

Volcanion (Wonder Guard)
B-
Aggron-Mega (Prankster, Fur Coat, Magic Bounce)

Alakazam-Mega (Psychic Surge, Harvest)

Banette-Mega (Huge Power)
Houndoom-Mega (Wonder Guard)

Kyurem-White (Magic Bounce)

Necrozma-Dawn-Wings (Wonder Guard)

Necrozma-Dusk-Mane (Huge Power, Magic Bounce)

Necrozma-Ultra (Huge Power,
Neuroforce*) *from Ultranecrozium Z Necrozma Dusk Mane or Necrozma Dawn Wings

Pikachu (Imposter)

Sceptile-Mega (No Guard)

Solgaleo (Prankster, No Guard, Sturdy)
C Rank

Articuno (Magic Bounce)

Dialga (Wonder Guard)

Giratina (Innards Out)

Guzzlord (Innards Out)

Heracross-Mega (Huge Power)

Kyurem-Black (Magic Bounce, Refrigerate)

Marowak-Alola (Huge Power)

Metagross-Mega (Harvest, Huge Power, Magnet Pull)
Type: Null (Wonder Guard, Magic Bounce)

Xerneas (Innards Out)
D Rank
Bisharp (Wonder Guard)

Beedrill-Mega (Huge Power)

Darmanitan-Zen (Wonder Guard)

Froslass (Magic Bounce)
Excadrill (Innards Out)
Gardevoir-Mega (Wonder Guard, Magic Guard)

Gyarados @ Gyaradosite (Wonder Guard, Illusion)
Magearna (Wonder Guard)

Mamoswine (Magic Bounce)

Mawile @ Mawilite (Simple)
E Rank
Everyone Else - Because really, this is USUM Pure Hackmons.