The drug accelerates Szayelaporro’s senses to the point where one second feels like centuries. While his mind perceives every movement in extreme slow motion, his body cannot react fast enough to move.
Mayuri slowly drives his Zanpakutō into Szayelaporro's heart. Due to the drug, the villain experiences the agony of the blade piercing him for what feels like hundreds of years. Bleach (Dub) Episode 199
Mayuri reveals he anticipated this move and placed various drugs inside Nemu. By resurrecting through her, Szayelaporro accidentally ingests a "Superhuman Drug". The drug accelerates Szayelaporro’s senses to the point