So uh we're coining two term that is new as far as we know of... sorry if this already exists
Ageregenic
A system/subsystem/sidesystem/headmate who's formation is in some way related to age regression
Examples of this could be
A headmate forming in order to care for another headmate who age regresses
A little forming after another regresses
A headmate being created to hang out while regressed
Or anything else related to age regression
Petregenic
A system/subsystem/sidesystem/headmate who's formation is in some way related to pet regression
Examples of this could be
A headmate forming in order to care for another headmate who age regresses
A animal headmate forming after another regresses
A headmate being created to hang out while regressed
Or anything else related to pet regression
Made for our friend