During your Draw Phase, if this card is in your Graveyard, you can add this card to your hand instead of drawing, and/or send 1 "Koa'ki Meiru" monster from your hand to your Graveyard to add this card to your hand.
Use these cards to search out Iron Core of Koa'ki Meiru from your deck.
Many powerful Iron Core support cards require you to have Iron Core of Koa'ki Meiru in your hand or to use as cost. Here are some of them.
Tag Duel Event [16 Aug - 27 Aug 2019]
Curse of Dread
Full Metal Desperado
Train Your Kuriboh! Campaign
2nd Anniversary Campaign
PvP Best decks [19 August Updated]
King of Game decks [August 2019]
V for Vendread: deck recipe
Triamid: deck recipe
Cyberdark Desperado: deck recipe
Leaked News [9 Aug updated]
Six Samurai Synchro: deck recipe [August 2019]
Red-Eyes Fusion: deck recipe
Dark Magician: deck recipe (After 2019 June)
Auto Duel Decks and Tips
Cyber Dragon: deck recipe
Sphere Kuriboh | Deck and Rulings