Diamond Core of Koa'ki Meiru

If you have multiple copies of "Iron Core of Koa'ki Meiru" in your hand, you can activate the effect of each to "Add 1 'Koa'ki Meiru' card, except 'Iron Core of Koa'ki Meiru', from your Deck to your hand."

The effect "During this turn, 'Koa'ki Meiru' monsters you control cannot be destroyed" is an effect that creates a Chain Link. (You activate this effect by banishing this card from your Graveyard as a cost.)

The effect "During this turn, 'Koa'ki Meiru' monsters you control cannot be destroyed" also prevents "Koa'ki Meiru" monsters that are summoned to your field after the effect is activated from being destroyed.

This applies not only to destruction by battle or card effects, but also prevents "Koa'ki Meiru" monsters from being destroyed when you choose "do neither and destroy this card" during the End Phase.

The application of the effect "During this turn, 'Koa'ki Meiru' monsters you control cannot be destroyed" ends at the end of the turn. (It does not end at an arbitrary timing during the End Phase.)