Substitute+Calm Mind Hoopa
Hoopa @ Aguav Berry
Ability: Magician
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Calm Mind
- Shadow Ball
- Psyshock
- Substitute
General idea
You may think that Calm Mind is generally outclassed by Nasty Plot, but the +1 SpD is really underrated a lot because it has a natural synergy with Substitute.
0 SpA Florges Moonblast vs. +1 0 HP / 4 SpD Hoopa: 60-72 (19.9 - 23.9%) -- possible 5HKO
0 SpA Diancie Moonblast vs. +1 0 HP / 4 SpD Hoopa: 55-66 (18.2 - 21.9%) -- possible 5HKO
0 SpA Empoleon Scald vs. +1 0 HP / 4 SpD Hoopa: 51-60 (16.9 - 19.9%) -- guaranteed 6HKO
In these examples, the Substitute is not broken with a single attack and Aguav Berry allows Hoopa to use CM one or two more times. Without the item, even Magician can be useful to steal one item before fainting.
With no HP EVs Hoopa has 301 HP, enough to make 4 Substitutes and keep itself alive at 1 HP.
A Timid nature is recommended in order to reach 262 Spe points, enough to speed tie with 252+ Spe Bisharp, Decidueye, Magneton and Volcanion.
Team(mates) support
A way to deal proporly with Pursuit users is recommended and, also, a slow U-turn/Volt Switch is recommended.