@kavinh I'm not sure who's the poor guy that took the no.2 position after Hikoichi got promoted to no.0...and then promptly dispatched by Kadokura but it has to happen between the ending of the Tower of God arc and the start of the Ban where he first appeared, maybe there was an offscreen ranking battle?
damn Usogui's truly a whirlpool in a maelstrom -- that is gamble. devouring anything, indifferent whether whatever above and/or below would survive its pull