Drifloon Valley
Somewhere north of Kalos, beyond Azure Bay and the Sea Spirit’s Den, there is a strange spot of land where Aipom and Ambipom live in crude, simple villages while the wildlands are inhabited by Drifloon and Drifblim. The owner of the Flying gym has set up in this strange spot of land, specifically in a valley travelled by many Drifloon. The valley has ample vegetation, so much so that moves like Nature Power treat the valley as an area of tall grass. A river runs through the valley, providing a source of water while the banks of the river have plenty of rocks that can be used. The main reason for these highly-populated Drifloon pilgrimages is the heavy winds experienced in the valley.
Here are some more details about this arena’s features:
Mild Sunlight
The weather in Drifloon valley is often quite pleasant, with the sun shining (but not too hot) and few (if any) clouds in the sky. This weather has the same effect as Sunny Day, except it does not alter the Base Attack Power of Fire- and Water-type attacks and does not cause Pokemon with Dry Skin to take ongoing damage. This form of sunlight is the default weather of the arena, replacing the normal clear weather. All other weather effects are permitted and work as normal, except that any Fog weather has its duration halved (rounded up to the nearest action)
A Lot of Drifloon
So many Drifloon travel along this valley that, if a Pokemon were to somehow fly above them, it would be partially concealed by them from the Pokemon below and it would have a degree of cover from such Pokemon. Thus, a Pokemon in the evasive stage of Bounce, Fly or Sky Drop cannot be hit by Pokemon not in that same stage, even by moves that normally can target them, unless either the user of the move or the target has No Guard. However, the concealment effect goes both ways, and so Fly has its base accuracy reduced to 85% and Bounce has its base accuracy reduced to 75%. Sky Drop doesn’t rely on being able to perceive a target on the ground while the user is in the air, so its accuracy is unaffected.
Heavy Wind
The strong wind currents the Drifloon use to float along the valley make aiming many projectile attacks harder. All attacks that require an external rock source have their base accuracy reduced by 10%, as do all attacks that Pokemon with the Bulletproof ability are immune to, with the exceptions of Gyro Ball and Ice Ball. This accuracy reduction is suppressed any time there is exactly one Tailwind effect up.
Summary
- Enough external sources and stuff for all moves to be used
- Terrain-based moves like Nature Power use "tall grass" setting
- Clear weather < Sunny Day minus Fire boost, Water nerf and Dry Skin damage
- Fog duration halved
- Pokemon in evasive stage of Bounce/Fly/Sky Drop can't be hit at all without help from No Guard
- Fly has 85% acc, Bounce has 75% acc
- Moves that need rock source and moves that Bulletproof Pokemon are immune to (other than Gyro Ball and Ice Ball) are 10% less accurate unless one team has Tailwind up