when he was young, lord english got beaten up by an alternate universe version of john bringing doomed timeline versions of the other kids with him (as seen in ACT 6 ACT 6 ACT 5, and revisited in the Meat timeline of the Epilogues). one of these is Jake English, the post-scratch version of Jade's grandpa. Jake is the one that gets to do the most. young Lord English, who hasnt yet changed his name to Lord English, decides that he respects this dude and steals his last name. then some stuff happens, and Lord English gets his Handmaid (the troll Doc Scratch was raising) to recruit Her Imperious Condesencion, aka Meenah Peixes, aka Betty Crocker. Betty Crocker raises her adopted meteor-human kids, Jake Crocker (later renamed to Harley) and Jane Crocker (later renamed to Egbert). Then more stuff happens and basically Acts 1-4 and Act 5 Act 2 happen, as Act 5 Act 1 had already canonically happened. Then they scratch their session, and HIC moves to the Post-Scratch timeline, where she instead raises Jade Crocker (later renames herself to Jade English to spite HIC, as English is the only person HIC is afraid of), and John Crocker, who doesnt rename himself. then stuff happens, and Epilogues John Egbert (pre-scratch) goes and gets some doomed timeline versions of the other kids, and they go fight young Lord English, who hasn't yet named himself Lord English.
so basically: paradoxes.
