Attribute Spirit

The "Attribute Spirits" are a group of monsters with "Spirit" 「精霊」 in their name; however, they are not Spirit monsters. They each belong to one of the four elemental Attributes: EARTH, FIRE, WATER, and WIND. Being Special Summon-only monsters, their conditions for being Special Summoned are that you must remove one of your monsters in your Graveyard with the same Attribute as it from play. There is another set of monsters with similar effects and conditions, but these do not include "Spirit" in their name, and some require you to remove two monsters of the proper Attribute instead of one. In the Yu-Gi-Oh! GX anime, these cards were part of Lyman Banner's/Amnael's Alchemy Deck, used as cost for Elemental Absorber. The Attribute Spirits (and Silpheed instead of Garuda) are related to this science, as they resemble the representation of the elements in alchemical symbology: The Rock Spirit resembles a dwarf, representative of the earth; Spirit of Flames resembles a salamander, representative of the fire; Silpheed resembles a sylphid, representative of the air; and Aqua Spirit resembles a nymph, representative of the water.

Their Japanese names share a naming pattern (Element "Spirit", Name) as follows:
 * The Rock Spirit = Rock Spirit, Titan (岩の精霊 タイタン)
 * Spirit of Flames = Flame Spirit, Ifrit (炎の精霊 イフリート)
 * Garuda the Wind Spirit = Wind Spirit, Garuda (風の精霊 ガルーダ)
 * Aqua Spirit = Water Spirit, Aquaria (水の精霊 アクエリア)

Effects and Stats
The Rock Spirit and Spirit of Flames have the same ATK and DEF and they have similar effects:
 * The Rock Spirit's ATK increases by 300 during its opponent's Battle Phase.
 * Spirit of Flames's ATK increases by 300 during its controller's Battle Phase.

Garuda the Wind Spirit and Aqua Spirit have the same ATK and DEF and have similar effects too:
 * Garuda the Wind Spirit can change the Battle Position of 1 face-up opponent's monster during the opponent's End Phase.
 * Aqua Spirit can change the Battle Position of 1 face-up opponent's monster during the opponent's Standby Phase.

Monsters with opposite Attributes have effects with opposite purposes too:
 * The Rock Spirit's effect has a defensive purpose and Garuda the Wind Spirit's effect has an offensive purpose.
 * Aqua Spirit's effect has a defensive purpose and Spirit of Flames's effect has an offensive purpose.

Usefulness
These monsters are good for swarming and Synchro Material because they can be easily Special Summoned from your hand.
 * You can use them as Tribute Fodder for the Tribute Summon of monsters of Level 5 or higher such as Monarchs. Furthermore, these monsters make it easier to activate effects that require multiple monsters as Tribute, such as the effects of Gilford the Lightning, Moisture Creature, and Beast King Barbaros.
 * Tribute Summoning is not the only way to get strong monsters. Since these Monsters are Special Summoned you can Normal Summon any Tuner Monster to Synchro Summon a Synchro Monster and get a strong monster in a single turn.
 * They have different Attributes, so you can use them in an Element Deck or a Charmers Deck. These monsters make the activation of Fuh-Rin-Ka-Zan easier.
 * The Rock Spirit, Gigantes, and the related Gigastone Omega can be used to raise the DEF of Lost Guardian or for their momentum-killing effects. They are also highly compatible with "Release from Stone."