Delta Stream (Ability ID: 191)

In-Game Description

"Strong Winds until switched out. Weather-based moves not usable."

Extended In-Game Description (280-300 chars)

Creates Strong Winds lasting until user switches. Reduces super-effective damage to Flying-types to neutral. Blocks all weather-based moves from hitting opponents. Cannot be overridden except by other primal weather. Protects all Flying Pokemon on field, not just user.

Character count: 293

Detailed Mechanical Explanation

Delta Stream creates the primal weather "Strong Winds" that provides unique Flying-type protection and weather move immunity.

Trigger Conditions

• Activates upon entering battle via onEntry hook
• Sets weather to ENUM_WEATHER_STRONG_WINDS (ID 7)
• Always succeeds unless another primal weather exists

Weather Properties

1. Primal Weather Classification:

   • Part of WEATHER_PRIMAL_ANY group
   • Cannot be overridden by regular weather
   • Only replaceable by Desolate Land or Primordial Sea
   • Regular weather attempts show "remained unchanged"

2. Duration:

   • Permanent while ability holder in battle
   • Ends when user switches out or faints
   • No turn counter or limit
   • Not affected by weather items

Primary Effects

1. Flying-type Damage Reduction:

   • Super-effective moves (2x or more) vs Flying-types → 1x damage
   • Affects ALL Flying-type Pokémon on field, not just user
   • Still shows "It's super effective!" but damage is neutral
   • Does not affect non-super-effective moves

2. Weather-Based Move Immunity:

   • Blocks ALL moves with FLAG_WEATHER_BASED
   • Only blocks when targeting opponents (self-targeting allowed)
   • Shows "Soundproof Protected" message (script reuse)
   • Affected moves include: Weather Ball, Solar Beam/Blade, Thunder, Hurricane, etc.

3. Unique Properties:

   • No weather damage (unlike hail/sand)
   • No type boosts/reductions
   • No accuracy changes
   • Pure defensive weather

Special Interactions

• Cloud Nine/Air Lock: Cannot suppress primal weather
• Weather Moves: Sunny Day, Rain Dance, etc. fail
• Multiple Delta Stream: Last one maintains effect
• Castform: No form change (no wind form)

Implementation Details

constexpr Ability DeltaStream = {
    .onEntry = /* Sets strong winds */,
    .onImmune = /* Blocks weather-based moves */
};

• Uses TryChangeBattleWeather for activation
• onImmune hook intercepts weather-based moves
• Script: BattleScript_DeltaStreamActivates

Strategic Notes

• Excellent for Flying-type teams
• Counters weather-based strategies
• Provides unique defensive utility
• Only primal weather with move blocking