Learn English – What does it mean “… the econothe goes arse over tit.”

"Go meta" refers to the action of doing things in a metaphysical manner, that is to say, in a way that considers the effects of one's actions, instead of simply acting them out. "Meta", in a broad sense, means "self-referential", examining the self and the self's actions while at the same time being that self and performing those actions.

It might help to thing of it as going "plus one level above" and acting as if you were watching yourself doing the action.

In this case, "normal" would be to simply say things that may cause discomfort or be manipulative in nature. To go "one level above", you would openly acknowledge that your actions may have said effects, and yet still act them out.

To "go meta" in a game, you would not just perform things that would get you a good score, but also things "above the game, only visible by an existence beyond the game (the player)", such as completing achievements. These achievements have no effect in the game, but are part of the entire experience for the player.

Jellicle is a fictional word made up by the poet T.S. Eliot in a series of poetry about cats that was later adapted into a musical (and also a much-mocked feature film). Jellicle Cats is the reference that ScreenRant is making there--the "Jellicle Ball," which the show Cats is centered on, is a story where the cat who is voted the winner of the Jellicle Ball gets to die and ascend to heaven or possibly some sort of reincarnation. The cat who wins is an elderly cat who has had a terrible life.

Since the character being discussed also wants to die after living for over 400 years, Ryan makes a joke by referring to his motivation as "jellicle."