505.1. Attack step consists of five substeps: "attack declaration", "block declaration", "battle", "direct attack" and "end of attack".
505.2. During the attack step, the active player can use their creatures to attack the non-active player or their tapped creatures.
505.3. Only creatures can attack and block.
505.4. Creatures attack and block one by one. It is not possible to attack or block with multiple creatures simultaneously.
505.5. The active player may declare attacks as long as they control a creature that is able to attack.
505.6. If an attacking or blocking leaves the battle zone, it is treated as not to be attacking or blocking. Some effects remove creatures from attacking. Creatures removed from 'attack' are attacking creatures, Whether you are a creature or a blocked creature, unprotected creatures It will be gone.
505.6a Once a creature has been declared to attack or block, it will not be removed from attacking or blocking even if an ability that prevents it from attacking or blocking was invoked after the declaration. However, if an attacking creature is removed from its attack by some effect, the attack ends immediately and the end of attack step starts.
505.6b Attacking and blocking creatures are not be removed from an attack even if their ownership changes or they become untapped.