"
Koa'ki Meiru", Japanese for "
Core Chimail" (コアキメイル
Koakimeiru), a combination of the words "Core", "Chimera" and "Mail"), sometimes romanized as "
Core Chimair" (a combination of the words "Core" and "Chimera,") is an
archetype of cards primary from
Raging Battle,
Ancient Prophecy,
Stardust Overdrive,
Absolute Powerforce and
The Shining Darkness. This archetype received more
Anti-Meta and support cards in later sets
Starstrike Blast,
Primal Origin and
Secrets of Eternity.
The majority of their effects center around manipulating the "
Iron Core of Koa'ki Meiru" or
revealing one in your hand to activate an effect. Almost all of the monsters require a maintenance cost in the form of sending an Iron Core to the Graveyard or revealing a monster of the same type. There are exceptions, such as that of "
Koa'ki Meiru Powerhand", where you must reveal a
Normal Trap Card, or "
Koa'ki Meiru Valafar" where you have to send an "Iron Core of Koa'Ki Meiru" and cannot reveal any card in your hand instead. Another is "
Koa'ki Meiru Ice", where a
Continuous Spell Card is revealed.
"Koa'ki Meiru" are all
EARTH,
WIND,
WATER or
FIRE Attribute monsters, rendering them immune to their own control-based effects, which often affect
LIGHT and
DARK monsters. All of the "Koa'ki Meiru" have the same mark (3 dragons) on some part of their body or on a weapon they have. Also, many "Koa'ki Meiru" and related cards' artwork uses yellow, orange, and red, except for "
Koa'ki Meiru Ghoulungulate".
According to "
Iron Core Specimen Lab", "
Kozaky" and "
Magical Scientist" experimented and created the "Koa'ki Meiru" Monsters.