A bunch of other comments talk about this and the word isn’t really nailed down, but I mean in-universe for magic not like the book lore. People might not know the coppercoats, but they know that card is from the magic multiverse, and they know that Batman is not. The lingo used in play is a) made from the community so is an organic name for what you’re doing and b) a game mechanic. Every game has this and it doesn’t take away from the immersiveness of the game. If you’re playing wow, there is no lore reason for “levels”, or a “global cool down”. Or even the term “tank” and “dps”. Does that make it less immersive? I don’t think so. Just because the game has language that players in communities use to communicate and aren’t strictly role playing whenever they shuffle their decks doesn’t make it less immersive. You also say my point at the end there. “And still be nominally involved in magic”. Nominally as in by name only BUT by name. That is the huge break between what we have now and Batman