Shaun & Rebecca, Agents
Legendary Creature — Human Assassin Scientist
Vigilance
When Shaun & Rebecca enters, search your graveyard, hand, and library for a card named The Animus and put it onto the battlefield, then shuffle.
: Add 
. When you do, mill two cards.
"Information is a weapon as potent as any Assassin's blade."
Gintas Galvanauskas
Assassin's Creed (ACR)
• #64Rulings
If you activate the mana ability of Shaun & Rebecca, Agents while in the process of casting a spell, activating an ability, or during a window to activate mana abilities when you're asked to pay a cost during the resolution of a spell or ability, you won't mill cards right away. Instead, a second "reflexive" ability triggers whenever you activate that ability. That ability won't go onto the stack until you're done casting, activating, or resolving that spell or ability, as appropriate. Each player may respond to that triggered ability as normal.
(wotc • 2024-07-05)
Rulings
If you activate the mana ability of Shaun & Rebecca, Agents while in the process of casting a spell, activating an ability, or during a window to activate mana abilities when you're asked to pay a cost during the resolution of a spell or ability, you won't mill cards right away. Instead, a second "reflexive" ability triggers whenever you activate that ability. That ability won't go onto the stack until you're done casting, activating, or resolving that spell or ability, as appropriate. Each player may respond to that triggered ability as normal.
(wotc • 2024-07-05)