An unidentified squad leader and his crew heading towards Arima and Kaneki? The only people I could see it being at this point are Hirako and Takeomi. "Let's head underground, Special Class Arima is alone" sounds weirdly shady though.
Papa Mougan and Aura are blocking the exits, they'll be outnumbered by quite a bit when Ayato and co. get there, pls no more Anteiku plot armour
Suzuya got stabbed in/near the heart, the "Squad leader...suicide?" line from chapter 79 still has me a little confused, we can rule out Arima, Mougan and Aura because Matsuri specifically mentioned not to report on the events in Cochlea, so that would leave Houji, Ui, Suzuya or Marude.
It's obviously not Marude because he was on the boat with Matsuri, and he doesn't seem like the sort of guy to commit Sudoku seppuku anyway, so It's either Houji, Ui or Suzuya.
With Suzuya being stabbed this chapter, it would be really out of place for him to commit suicide, and it doesn't really fit his character considering how much emphasis Ishida's been putting on him valuing his life.
So I guess it would have to either be Houji or Ui?