What it does
Stored Power is a Psychic-type Special move. The base power starts minimal, but each positive stat stage on the user adds 100% of the original base power to the total. Accuracy and evasion changes don't count, reduced stats don't count — only positive stat stage raises. All five offensive/defensive stats at +6 gives a multiplier that makes the move's power enormous.
In practice, Stored Power builds don't usually try to reach maximum stacking — the cost is too high. The realistic model is: a few turns of Calm Mind (each giving +1 Special Attack and +1 Special Defense, so +2 stages per use) already push the power high enough to become threatening. Shell Smash at +2 Attack, +2 Special Attack, and +2 Speed in one move gives six stages of positive raises in a single turn — Stored Power's power scales immediately into KO range with that move.
Psychic type hits Fighting and Poison super-effectively. It's immune to Dark-type Pokémon entirely — Stored Power doesn't land on them.
Who runs it
Polteageist (34% usage) is the primary carrier. It can run Shell Smash, which delivers six positive stages in one turn: +2 to Attack, Special Attack, and Speed. After Shell Smash, Stored Power's power becomes extreme, and the +2 Special Attack boost makes the actual damage output threatening. Its Ghost typing doesn't interact with Stored Power's Psychic coverage, but against neutral or Psychic-weak targets the numbers are real.
Klefki (9% usage) uses Stored Power in configurations involving Calm Mind or other accumulation mechanics. At 9% usage it's a niche choice, situation-specific.
How to use it
Stored Power requires setup first. At base stages, it deals minimal damage — you don't click it on turn one without boosts. At least a Shell Smash or two Calm Mind turns in, it starts to hit real numbers.
In doubles, the setup turns need cover. If you're using Calm Mind or Shell Smash while your partner handles the opposing side with Follow Me, Rage Powder, or just bulk, that's what makes Stored Power builds viable. Naked setup into two opponents without protection almost always gets interrupted.
Tips & strategy
Dark-type Pokémon are immune to Psychic — Stored Power does nothing against them. Any Stored Power build needs coverage for common Dark-type core Pokémon in the format.
Baton Pass chains can relay accumulated stages to a Stored Power user — extremely powerful in theory but requires full chain team construction, which is difficult in doubles.
Stat drops on the user don't count toward Stored Power's scaling — only positive raises matter. Clear Amulet on the opponent side only blocks their stat reductions, not your positive stat accumulation. The power scaling is entirely yours.