Shaymin
Grass → Grass
Natural Cure → Purifier (Immune to Poison type moves, Poison type moves restore 25% of max HP)
100/100/100/100/100/100 (600) → 100/115(+15)/130(+30)/115(+15)/130(+30)/110(+10) (700)
Shaymin's Pokedex entries mention that it's able to remove toxins from the air in the area it's in, thus the new ability. While not necessarily as good as Natural Cure is, Purifier gives Shaymin not only an immunity instead of a weakness, but also, just as an importantly, an immunity to Toxic which, as a more defensive oriented Pokemon, gives Shaymin a huge amount of walling potential.
Phione
Water → Water
Hydration → Water Absorb
80/80/80/80/80/80 (480) → 80/80/110(+30)/100(+20)/110(+30)/100(+20) (600)
+Recover, heal bell
Unlike its cousin Manaphy, M-Phione attempts to be a bulky water type, Water Absorb recovering ¼th of its HP from opposing water movies and Recover and Heal Bell doing the rest.
Cresselia
Psychic → Psychic
Levitate → Levitate
120/70/120/75/130/85 (600) → 120/80(+10)/150(+30)/95(+20)/160(+30)/95(+10) (700)
+Recover
Recover is a bit more reliable than Moonlight
Victini
Fire/Psychic → Fire/Psychic
Victory Star → Simple
100/100/100/100/100/100 (600) → 100/133(+33)/134(+34)/100/133(+33)/100 (700)
+Play Rough
Victini is one of those Pokemon that it's difficult to give a 100 point stat increase too without making it OP. Normally giving Simple to a Pokemon is pretty ridiculous since it's such a good ability. Vicitini, however, has only three moves that give it a positive boost all of which are very weak (Flame Charge, Charge Beam and Power-Up Punch) and very unlikely to be useful on any M-Victini set.
Meanwhile the move it loves to spam in V-Create has its drawback heavily increased since it now decreases Victini's defense, SpD and speed by two stages every time it uses which combined with Victini losing 25% of its HP every time it switches in if Stealth Rock is up and no form of recovery outside of rest means it's usually not going to last long.
Grass → Grass
Natural Cure → Purifier (Immune to Poison type moves, Poison type moves restore 25% of max HP)
100/100/100/100/100/100 (600) → 100/115(+15)/130(+30)/115(+15)/130(+30)/110(+10) (700)
Shaymin's Pokedex entries mention that it's able to remove toxins from the air in the area it's in, thus the new ability. While not necessarily as good as Natural Cure is, Purifier gives Shaymin not only an immunity instead of a weakness, but also, just as an importantly, an immunity to Toxic which, as a more defensive oriented Pokemon, gives Shaymin a huge amount of walling potential.
Phione
Water → Water
Hydration → Water Absorb
80/80/80/80/80/80 (480) → 80/80/110(+30)/100(+20)/110(+30)/100(+20) (600)
+Recover, heal bell
Unlike its cousin Manaphy, M-Phione attempts to be a bulky water type, Water Absorb recovering ¼th of its HP from opposing water movies and Recover and Heal Bell doing the rest.
Cresselia
Psychic → Psychic
Levitate → Levitate
120/70/120/75/130/85 (600) → 120/80(+10)/150(+30)/95(+20)/160(+30)/95(+10) (700)
+Recover
Recover is a bit more reliable than Moonlight
Victini
Fire/Psychic → Fire/Psychic
Victory Star → Simple
100/100/100/100/100/100 (600) → 100/133(+33)/134(+34)/100/133(+33)/100 (700)
+Play Rough
Victini is one of those Pokemon that it's difficult to give a 100 point stat increase too without making it OP. Normally giving Simple to a Pokemon is pretty ridiculous since it's such a good ability. Vicitini, however, has only three moves that give it a positive boost all of which are very weak (Flame Charge, Charge Beam and Power-Up Punch) and very unlikely to be useful on any M-Victini set.
Meanwhile the move it loves to spam in V-Create has its drawback heavily increased since it now decreases Victini's defense, SpD and speed by two stages every time it uses which combined with Victini losing 25% of its HP every time it switches in if Stealth Rock is up and no form of recovery outside of rest means it's usually not going to last long.