I know I'm late with this as #11 is being released tomorrow lol, but I've just read this issue and didnt find a review thread for it, which is a bit surprising after the revelation.

So the leader of the 2 billions old society Threshold is none other but Okkara himself.

What happened in this issue shortly: the Marauders were fighting Arkea and Sublime and Cassandra defeated them. Kate took her revenge on Cassandra for what she did and they left her in the past. The war is still happening with the Unbreathing, but Grove says it's their fight and asks the Marauders to go home back to the present.
Grove has a new look (his healing is vegetative) and chooses a new name, Okkara.
I have no idea what Stryfe was doing on Threshold, but he helped the Unbreathing to defeat Threshold.
Back on Krakoa they resurrect the Threshold Three, so at least 3 Thresholders are alive in the present.