Cloudian

The Cloudians (雲魔物 クラウディアン, Kuraudian) set are a series of monsters and their support cards introduced by Adrian Gecko in the Yu-Gi-Oh! GX anime. They are all WATER-Attribute Fairy-Type, with the exceptions of "Cloudian - Eye of the Typhoon", "Cloudian - Poison Cloud", and "Cloudian - Ghost Fog"; "Cloudian - Eye of the Typhoon" is WIND Attribute, while "Cloudian - Poison Cloud and "Cloudian - Ghost Fog" are Fiend-Types.

Many of these monsters can't be destroyed in battle when in Attack Position, but if they are in Defense Position they are destroyed by their own effect. Spirit Barrier and Sanctuary in the Sky protects your Life Points while you have a face-up Cloudian monster in Attack Position, especially if it is a Cloudian that cannot be destroyed in battle. Many also have low attack scores, but this means that a majority are searchable by the Elemental Seachers, "Salvage", and "Sangan". Cloudians have their effects activated with "Fog Counters". "Cloudian - Smoke Ball" is the only Normal Cloudian monster.

Play Style
Cloudians require a moderate degree of skill to use properly, because their main forces depends on how much "Fog Counters" there are on the field. Cloudians cannot be destroyed by battle, but their low ATK leaves their controller open to taking damage unless "Spirit Barrier" or "The Sanctuary in the Sky" are used. Once those cards are in play, however, the opponent will have a frustrating time attempting to get past a Cloudian-user's defenses. While the opponent is being stalled, the Cloudian user can then generate enough Fog Counters to whittle down the opponent's defenses, eventually leaving them with nothing to protect themselves from the otherwise "weak" monsters.

Strategy
Cloudians, because they are WATER Attribute Fairy-Type monsters, are very versatile with a lot of support cards, both Cloudian and non-Cloudian. A Cloudian Deck can focus on swarming the field, on destroying the opponent's cards, on inflicting Burn Damage with Natural Disaster, on a Stall Victory, on raw Beatdown power with Cloudian - Nimbusman, or any combination of the above. Cloudian - Eye of the Typhoon can also provide some field control, by messing with the battle positions of your opponent's monsters.

Fog Counters
The main force for Cloudian Monsters. They are essential for the victory of a Cloudian Deck. These counters should be mainly placed on the Cloudian player's monsters but certain Cloudian cards can use the placing of "Fog Counters" upon the whole field. ex: Cloudian - Nimbusman, Diamond-Dust Cyclone and Updraft

Since "Fog Counters" can only be placed on face-up monsters, Light of Intervention is a good card to have in a Cloudian Deck. A good way to strenghten your field monsters is to have Cloudian Squall on the field and maybe use some stalling cards to pass turns and put more "Fog Counters" on the current face up monsters.