Put the top card of your deck into your EX area. Repeat until your EX area is full.
At the start of your next end phase, banish each card in your EX area.
QIf I play this spell during my opponent's turn, do I banish the cards in my EX area at the start of their end phase?
ANo. It only happens at the start of your own end phase.
QIf I play this spell, at the start of my next end phase, do tokens in my EX area also get banished?
AYes. All cards in your EX area get banished.
QIf I play this spell, at the start of my next end phase, do cards that were not put into my EX area by this spell also get banished?
AYes. All cards in your EX area get banished.
QIf my EX area has reached its card limit, can I still play this spell?
AYes, you can. However, no cards will be added to your EX area.