These Ruling(s) have not been confirmed as applicable to the TCG.[Notes 1]
In place of declaring a FULL card name, a precise description of a card's stats, appearance, and/or effects, is considered acceptable so long as both players are in clear agreement over which card is being described.
If the declared card is already on the field, then that card can no longer be used.
If "Psi-Blocker" is not face-up on the field when its effect resolves, then you still cannot use the declared card.
If "Psi-Blocker" is removed from the field after its effect finishes resolving, then you still cannot use the declared card.
↑Konami Judge Program Rulings are considered unverified, as their source(s) are not publicly viewable. They are not confirmed as applicable to the TCG until they have been officially published by Konami.