Relgas y mas reglas

No se si recordareis la situación en europeo entre Alessandro y Grunner donde Grunner intenta atacar con ciber fénix a un raiza y pregunta si el rival hace algo e intenta activar enemy controler para pasar el raiza a defensa en ese momento se dijo que no y el fénix se empotro

Pos acaba de salir una regla sobre ello

When an attack is declared, the Turn Player can retain priority to activate effects. At this time they are free to activate cards that perform an action when a monster attacks or any other effect with timing they can meet.
If the Turn Player decides that they will pass, their opponent is given a chance to activate effects that respond to the attack (Sakuretsu Armor, Mirror Force, etc.) or any other effects with timing they can meet.
If the Turn Player passes, and the opponent passes as well, the chance to use effects with like that of "Sakuretsu Armor", "Mirror Force", "Magic Cylinder", etc. is GONE.
Now, the Battle Step doesn't immediatly fast forward to the Damage Step. Players can still activate effects in the Battle Step. However, at this point it is too late to use cards that need to respond to an attack. "Enemy Controller" or "Book of Moon", for example, would still be possible at this point.

Now what happens if a Chain is activated in response to the attack declaration and the attacking monster survives the Chain? For example, the opponent activates "Sakuretsu Armor" and the turn player uses "Trap Jammer" to negate it. Can the opponent begin another Chain with "Mirror Force"?
The answer is no. There is only one Chain that can be used to respond to the declaration of the attack. When this Chain resolves, or is completely passed on by both players, the Battle Step will only allow for Chains that don't involve cards that need to respond to an attack.

En resumen es que cuando declaras un ataque y no respondes tu rival puede responder si el pasa prioridad ya no se puede activar nada tipo mirror sakuretzu o cilindros pero luego hay otra fase antes de la damage step que es donde se pueden activar cartas tipo enemy, book of moon, ring etc…