This page presents a guide for the Yu-Gi-Oh! Millennium exclusive monster type, Evolution Monsters.
Basic Description: Evolution Monsters are Extra Deck monsters with a metallic silver card border that features a circuit board-like pattern. They are summoned via Evolution Summoning, also known as Evolving.
How to summon one: Each Evolution Monster has a printed requirement on top of the effect. The requirement could be anything from a specific monster, to a type of monster, to monster that meets certain requirements. Only one monster is used in an Evolution Summon. Once you have the required monster on the field, take the appropriate Evolution Monster from your Extra Deck and place it on top of the required monster. The required monster is known as the Evolution Base. In a duel using Link Summoning rules, an Evolution Monster is still able to be summoned to an unlinked Normal Monster Zone, as Evolution Monsters must occupy the same zone that their Evolution Base occupied, so the one Extra Monster Zone rule does not apply to them. Note: Evolution Monsters cannot act as the Evolution Base. One notable exception are Darkness Evolution monsters, which can due to the effect of Corruption of Darkness.
Once on the field: Evolution Base monsters do not count as a card on the field, and as thus can only be affected by cards that specifically target an Evolution Base. Otherwise, Evolution Monsters count as regular monsters while on the field. If an Evolution Monster would be destroyed or banished, it instead is sent to the Devolution Zone.
Devolving: During the end phase, all of the Evolution Monsters of the player whose turn it is devolve . That means that the Evolution Monster is placed in the Devolution Zone, and that the Evolution Base returns as a monster on the field. When a monster devolves, the Evolution Base is not considered to be summoned to the field at that time. Note: If a card effect prevents an Evolution Monster from devolving at the end of one turn, it will devolve during the owners next turn, assuming the monster is no longer prevented from devolving.
The Devolution Zone: The Devolution Zone is a card area similar to the Banished Pile. In order to avoid the confusion of having an Evolution Monster without an Evolution Base (Such as if that monster was summoned by the effect of Monster Reborn), destroyed Evolution Monsters are sent here instead of the graveyard. The Devolution Zone is considered separate from the Graveyard and the Banished Pile, and as thus, can only be affected by cards that target the Devolution Zone specifically. On a duel field, it should be placed on the left of the Extra Deck Zone.
Variants: There are several variants of the Evolution Summon, each with their own mechanics and rules.
Chaos Evolution/Evolution of Order: These two variants are essentially the same thing, and actually aren’t that different from normal Evolution Summons. There are only two differences. In order to perform one of these summons, an extra requirement must be met. In the case of a Chaos Evolution, one Light and one Dark monster must be banished from the graveyard. In the case of an Evolution of Order, two Light monsters must be returned from the graveyard to the deck. The second difference is that when the end of the turn comes, their devolution can be delayed if the player repeats the initial requirements of banishment/returning. These differences from normal Evolution mechanics are listed in the card’s effect. It is having these effects that classify a monster as one of these types. Chaos Evolution Monsters are either Light or Dark attributes, while Evolution of Order Monsters are always Light.
Darkness Evolution: Darkness Evolutions are the exception to the rule of not being able to evolve an Evolution Monster, but in order to do so, the player must control a card with a continuous effect that allows them to, normally this card is the Continuous Spell Card Corruption of Darkness. Darkness Evolutions always have the term Darkness Evolution in their name, will list an Evolution Monster as an Evolution Base, and are always Dark Attribute. Also, the effect of Corruption of Darkness prevents Darkness Evolution monsters from devolving as long as its effect remains active. Variants of this form of Evolution summoning include Supreme Darkness Evolution, which is the evolution of a Darkness Evolution, and Pinnacle Darkness Evolution, which is an evolution of Supreme Darkness Evolution.
Celestial Apex Evolution: This method is mostly normal, except for the fact that an effect of a card with Celestial Advancement in its name is needed to trigger the evolution. There are many different Celestial Advancement cards with different secondary effects that fit into many different decks. Celestial Apex Evolution monsters are identified by their effects stating that they must be summoned by the effect of a Celestial Advancement card.