Capture Sphere

Most permanent removal-by-enchantment is sorcery-speed by default, which means the answer always arrives on your own turn and the opponent gets to sequence into it. The flash clause rewrites that math. This aura can land at instant speed, and the enters-tapped trigger lets it function as a preemptive combat answer: hold it up through an opponent's beginning-of-combat step and tap down a threat before attackers are declared, or drop it in response to a freshly resolved creature before it ever gets to swing. It locks the creature down twice over, tapping it on the way in and then denying the untap, so the body stays inert without needing to leave the battlefield at all. That distinction matters against indestructible or recursive threats that shrug off destruction but have no answer to simply never standing up again. The cost of the flexibility is the cost every aura pays: it is a two-for-one waiting to happen, vulnerable to bounce, sacrifice, and any effect that moves the creature, at which point the sphere goes to the graveyard for nothing. It is a softer lock than exile and a slower one than a kill spell, but the instant-speed window buys back enough tempo to make the trade worthwhile when the goal is to neutralize one specific attacker before it can act.