A couple of questions about what happened during Caliborn's Shitty Claymation Masterpiece; he said/showed that he and ARquiussprite and Half of Gamzee were sucked into the Cal Juju. Does that mean that Lord English is some kind of Amalgamation between Caliborn, Gamzee and ARquiussprite? Also, has it been explaine WHEN this happened? Was this something that was changed by the retcon or is it still Going to happen?

Yes, this means LE is a fusion (haha) of all those characters. The fight between the kids and Caliborn will most likely happen further along the current timeline we’re on now.