I'm about 90% sure that the collector is Rufus Zeno. But there are many other people that could be possible for the collector. It could also be Jerome's Dad. Some people are also saying that Rufus Zeno is Jerome's Dad. Hope this helps!
It's not Vera because in last night's episode they showed Vera step out of a car with the collector. Rufus could be it. He could have faked his death and became the collector. But we should find out Monday.
I think that the collector is Rufus because in the show when the collector came, Vera was seguinte to the collector so it can not be her. Also previously in season 1 Rufus was bitten por poisonous flies so he had bumps on his face. He probably wore the mask to keep the bites hidden. Who do you think it is?