Originally Posted by
TresserT
Firstly, Orion giving up his Grand status in Atlantis means that iteration of Orion lost the Grand class container. There's nothing stopping the world from just summoning Orion again as a Grand. It's like how in FZO Diarmuid breaks his spear, and then that iteration of Diarmuid no longer has the spear, but that doesn't stop anyone else from summoning Diarmuid with that spear. The only grand who can never be summoned again i ls Solomon for obvious reasons.
Secondly, I took the 7 Grands she fought to be placeholders. In the same way Shadow Gil was used as a placeholder for QSH back during Jing Ke's old interlude. But that's just how I took it.
Thirdly, Fate has never been about power levels, it's always been about type matchups. We don't know the full deal behind Kuku or Tezcat (or even Olga for that matter), and Olga does state that the fight with seven grands was epic and she did get injured during it. Tezcat might be equal to Kuku in terms of power, but he may have had a worse matchup than she does. Plus given Tezcat's personalify he could very easily have been jobbing. He's someone who just wants lots of death, so there's really no reason for him to be super against Olga.
Relatedly, I find it kind of weird that Tezcat is Grand Berserker (and I don't think it was actually confirmed in chapter? Just assumed, albeit fairly). With Quirinus it was hammered pretty hard that gods can't become Grands and that Quirinus was a huge exception.