Vizier of Deferment's triggered ability can target any creature, but it will affect a creature only if that creature was declared as an attacker or blocker this turn, whether you cast Vizier of Deferment during combat or later in the turn. Notably, the ability won't affect a creature that entered the battlefield attacking or blocking.

After the target creature returns to the battlefield, it will be a new object with no connection to the creature that was exiled. It won't be in combat or have any additional abilities it may have had when it was exiled. Any counters on it or Auras attached to it are removed, and any Equipment will no longer be attached.

A token creature exiled this way won't return to the battlefield.