TCG Rulings

• This effect targets 1 "Koa'ki Meiru" card in your Graveyard. ^[1]

• If this card battles a monster with the same ATK and both are destroyed, its effect will activate.^[1]

OCG Rulings

• The effect of "Koa'ki Meiru Crusader" targets one "Koa'ki Meiru" card in your Graveyard.^[2]

• If "Koa'ki Meiru Crusader" battles with a monster with equal ATK and both monsters are destroyed by battle, then you can activate the effect of "Koa'ki Meiru Crusader" and return one "Koa'ki Meiru" card to your hand.^[3]

Koa'ki Meiru Monster Rulings

TCG Rulings

• The first sentence of this card is a maintenance cost, not an effect. It does not start a Chain.^[4]

Mentions in Other Rulings

• Iron Core of Koa'ki Meiru: While “Macro Cosmos” is active, you cannot send “Iron Core of Koa’ki Meiru” to the Graveyard to pay the cost of keeping your “Koa’ki Meiru” monster on the field. So you must either pay the reveal cost, or destroy the monster.

OCG Rulings

• The text "During each of your End Phases, destroy this card unless you send 1 "Iron Core of Koa'ki Meiru" from your hand to the Graveyard [or else]." of "Koa'ki Meiru" monsters is a Maintenance Cost.^{[5][6][7][8][9][10][11][2][12][13][14][15]}

• While your hand is revealed by the effect of "Respect Play"/"Ceremonial Bell"/etc, you cannot perform "reveal 1 Normal Trap Card from your hand." as a Maintenance Cost for "Koa'ki Meiru Powerhand". You must either perform either "send 1 "Iron Core of Koa'ki Meiru" to the Graveyard" or "destroy this card".^[16]

• While "Macro Cosmos" is activate, you cannot perform "send 1 "Iron Core of Koa'ki Meiru" to the Graveyard" as a Maintenance Cost for "Koa'ki Meiru Doom". You must either perform either "reveal 1 Fiend-Type monster from your hand." or "destroy this card".^[17]

• The text "During each of your End Phase, destroy this card unless you send 1 "Iron Core of Koa'ki Meiru" from your hand to the Graveyard." of "Koa'ki Meiru Valafar" is a Maintenance Cost. It cannot be negated by the effect of "Skill Drain", so you must still pay the Maintenance Cost during your Standby Phases ^[sic].^[18]

References

1. ↑ ^{1.0 1.1} Shriek TCG: Ancient Prophecy - Rulings
2. ↑ ^{2.0 2.1} Konami FAQ: Koa'ki Meiru Crusader
3. ↑ Konami FAQ: Can the effect of "Koa'ki Meiru Crusader" be activated when it and the other battling monster are both destroyed?
4. ↑ Konami Gameplay FAQ: Raging Battle Sneak Peek -- Card Rulings (version 1.2) [Koa’ki Meiru Valafar , Koa’ki Meiru Powerhand , Koa’ki Meiru Guardian , Koa’ki Meiru Drago , Koa’ki Meiru Ice , Koa’ki Meiru Doom]
5. ↑ Konami FAQ: Effect Monster > Koa'ki Meiru Doom
6. ↑ Konami FAQ: Effect Monster > Koa'ki Meiru Ice
7. ↑ Konami FAQ: Effect Monster > Koa'ki Meiru Drago
8. ↑ Konami FAQ: Effect Monster > Koa'ki Meiru Guardian
9. ↑ Konami FAQ: Effect Monster > Koa'ki Meiru Powerhand
10. ↑ Konami FAQ: Effect Monster > Koa'ki Meiru Valafar
11. ↑ Konami FAQ: Effect Monster > Koa'ki Meiru Speeder
12. ↑ Konami FAQ: Effect Monster > Koa'ki Meiru Rooklord
13. ↑ Konami FAQ: Effect Monster > Koa'ki Meiru Sea Panther
14. ↑ Konami FAQ: Effect Monster > Koa'ki Meiru Urnight
15. ↑ Konami FAQ: Effect Monster > Koa'ki Meiru Sandman
16. ↑ Konami FAQ: Can a Trap Card in the hand be shown as a Maintenance Cost for "Koa'ki Meiru Powerhand" while the hand is revealed by the effect of "Respect Play"?
17. ↑ Konami FAQ: While "Macro Cosmos" is active, can a "Iron Core of Koa'ki Meiru" be sent to the Graveyard as a Maintenance Cost for "Koa'ki Meiru Doom"?
18. ↑ Konami FAQ: Can the effect of "Skill Drain" negate the Maintenance Cost of "Koa'ki Meiru Valafar" etc?