Crystal Beast Deck

Overview
Every Crystal Beast deck will include some (but not necessarily all) of the following monsters:
 * Crystal Beast Cobalt Eagle
 * Crystal Beast Amethyst Cat
 * Crystal Beast Topaz Tiger
 * Crystal Beast Ruby Carbuncle
 * Crystal Beast Amber Mammoth
 * Crystal Beast Sapphire Pegasus
 * Crystal Beast Emerald Tortoise

Crystal Beasts also have many support cards to go with and aid any strategy the duelist using them may have in mind. They are as follows:
 * Ancient City - Rainbow Ruins
 * Crystal Abundance
 * Crystal Blessing
 * Crystal Beacon
 * Crystal Release
 * Crystal Tree
 * Crystal Promise
 * Rare Value
 * Crystal Raigeki
 * Crystal Pair
 * Crystal Counter
 * Last Resort (Ancient City - Rainbow Ruins support)
 * Rainbow Gravity (Rainbow Dragon and Rainbow Dark Dragon support)
 * Rainbow Path (Rainbow Dragon support)

Because of Crystal Beast's universal effect of transferring to the Spell & Trap Card Zone as Continuous Spell Cards when destroyed, some decks will also use cards that are influenced by Continuous Spells. Magna-Slash Dragon, Seismic Crasher, Gravi-Crush Dragon, Hamon, Lord of Striking Thunder, and Dweller in the Depths are examples of this type of Crystal Beast manipulation. The monster Rescue Cat is also an invaluable tool. With its effect, you can Special Summon Crystal Beast Amethyst Cat from the deck with ease.

Rainbow Dragon
Rainbow Dragon is a powerful asset to a Crystal Beast deck, and if you play your cards right it can be fairly easy to summon. If you decide to focus on Rainbow Dragon, be sure to add cards like Rainbow Gravity, Rainbow Path, Crystal Pair and Crystal Tree. These four are more useful in a Rainbow Dragon deck, so it's not recommended to add them to any other Crystal Beast decks. Also, it is possible to use Magical Merchant, in conjunction with Monster Reincarnation/Rainbow Gravity, to get Rainbow Dragon out of the deck, and the Crystal Beasts needed to summon it into the graveyard. Have three copies of Crystal Beast Sapphire Pegasus and Crystal Beast Ruby Carbuncle at your disposal, and two copies of the others to maximize the probability of summoning Rainbow Dragon.

Crystal Abundance OTK
The OTK is more competitively friendly. It utilizes Crystal Abundance's effect to work, so a few copies of the card is essential to have in the deck, as well as a way to search it out (Different Dimension Capsule or Gold Sarcophagus work nicely). There must be four Crystal Beasts in the Spell & Trap Zone, plus an open slot to activate Crystal Abundance. Wait until you have five Crystal Beasts on the field or in your graveyard with attacks of 1600 or more to activate the card. Upon activating Crystal Abundance, if your opponent had at least five cards on his/her field, all five of your monsters can be Special Summoned. Crystal Abundance leaves your opponent open to a direct attack.

Aggressive Crystal Beasts
This deck is a very powerful and dangerous build that relies on either depleting your opponent's life points fast, or destroying your opponent's cards fast. If you plan to burn through your opponent's life points, Seismic Crasher and Gem Flash Energy are good cards to include. If card destruction is your goal, then you should use cards like Magna-Slash Dragon, Gravi-Crush Dragon and Crystal Raigeki. Also, Dweller in the Depths and Hamon, Lord of Striking Thunder are general beatsticks for delivering the final strike, and Ancient City - Rainbow Ruins is a strong defensive card that doesn't take up a Spell and Trap Card Zone slot, so they are good assets. For both of the above strategies, it is absolutely essential to keep the number of Crystal Beasts in your Spell and Trap Card Zone high, so some common cards are Kuraz the Light Monarch, Crystal Beast Sapphire Pegasus, Crystal Blessing, Crystal Tree and Crystal Counter.

Synchro-Crystal Beasts
This deck focuses on the synergy of the Crystal Beasts with Stardust Dragon and Red Dragon Archfiend. Red Dragon Archfiend is used to easily destroy your own Crystal Beasts, while Stardust Dragon helps to solidify the back row Crystal Beasts, giving Ancient City - Rainbow Ruins a strong place in this deck. It is a good idea to play Crystal Abundance in this deck as well, due to its OTK potential. Rose, Warrior of Revenge is great in this deck because the stronger, more useful Crystal Beasts are four star monsters (Crystal Beast Amber Mammoth, Crystal Beast Sapphire Pegasus, and Crystal Beast Topaz Tiger), making it easy to summon Stardust Dragon. Emergency Teleport and Krebons also help to summon the very useful Goyo Guardian in this build.

Monsters

 * Rainbow Dragon
 * Crystal Beast Ruby Carbuncle
 * Crystal Beast Topaz Tiger
 * Crystal Beast Amber Mammoth
 * Crystal Beast Sapphire Pegasus
 * Crystal Beast Amethyst Cat
 * Crystal Beast Emerald Tortoise
 * Crystal Beast Cobalt Eagle
 * Magical Merchant
 * Magna-Slash Dragon
 * Gravi-Crush Dragon
 * Hamon, Lord of Striking Thunder
 * Kuraz the light monarch

Spells

 * Ancient City - Rainbow Ruins
 * Crystal Abundance
 * Crystal Blessing
 * Crystal Beacon
 * Crystal Release
 * Crystal Promise
 * Rare Value
 * Lightning Vortex

Traps

 * Rainbow Gravity
 * Last Resort
 * Crystal Pair - If you play a Rainbow Dragon deck, you may use this to get out other Crystal Beasts. It can be used to protect your Life Points and get another Crystal Beast from your deck that you need.
 * Crystal Raigeki
 * Mirror Force