Terrors of the Afterroot — Ruling

Effetto 1

About this card's ① st effect:
This effect is the effect of this card's Card Activation.
You cannot activate it during the Damage Step.
When this effect resolves, you first『Special Summon [the targeted monster] to their field.』If you succeeded in doing so, you can then choose to『banish 1 monster they control.』If this also succeeds, you will then『return 1 of their banished monsters to the Graveyard.』
If you choose to banish a card, doing so is not treated as happening simultaneously with the Special Summon.
Banishing a monster and returning a monster to the Graveyard are not treated as happening simultaneously.

About this card's ② nd effect:
This is an activated effect, which can be activated in the Graveyard.
You cannot activate it during the Damage Step.
When this effect resolves,『shuffle [the targeted monster] into the Deck.』If you succeed in doing so, you can then『Set 1 "Terrors of the Underroot", "Terrors of the Overroot", or "Terrors of the Afterroot" directly from your Deck.』
If you choose to Set a card from your Deck, this is not treated as happening simultaneously with the monster being returned to the Deck.