Today’s Rules Tip written by Jen Wong
Bouncing an enchantment with Floodtide Serpent doesn’t use priority or the stack.
Flood the board with enchantments, and you’ll have some interesting choices to make when you attack with Floodtide Serpent. Similar to Sphere of Safety’s ability, the Serpent has a cost associated with attacking, and it’s paid as soon as you declare an attacker, without using the stack. Because of this, it also means that your opponent doesn’t have priority to do anything in-between you choosing the enchantment and having it returned to your hand. If your opponent wishes to stop the Serpent from attacking, the only sure way of doing that is to remove all your enchantments from the battlefield during the beginning of combat step, which is the last time he has priority before you start declaring attackers.