Implosion Seal is a specialized Storage Seal, and it is invented by Gōketsu Kagome. It instantaneously seals all the air within 5-20 m. (Exact radius set at creation time.) Anyone caught in the AoE gets to have their lungs implode as the air sucked out of them. The tag is destroyed by the inrushing air, which causes all the air that it sealed to reappear in a small area, at which point it goes surging out with enough force to wreck a building.
The hivemind has a design called Stacked Implosion Nuke, abbreviated SIN, which promises massive explosive power. To date, the design have yet to be tested.
The implosion seal was used by Kagome to clear out invisible air spike caused by a failure to infuse skywalker. It worked and cause the air spike to disappear.