Again, I keep finding myself flip-flopping on my thoughts on this. On one hand, this is clearly a huge tribute to Magic the Gathering, with the manga practically telling readers to use the normal MtG rules to fill in the gaps it leaves out. Almost everything from the names to the card designs themselves is blatantly referencing the game. It feels like this should be what log Horizon is to MMO's, with as much care and detail put into the combats to make logical sense.
Yet as each new chapter involving combat drops, things just feel off. The author really hasn't shown much if any differences between the card game and the world the MC appeared in. As such the readers come to the same conclusion the MC does, everything about the world works exactly the same as the MtG card game. Only that isn't true. Card mechanics feel a bit poorly defined at times, and certain abilities flat out shouldn't work that way according to the card game. There's no comment from the MC about multiplayer rules or Range of Influence. Heck, there was barely a mention of how they lost the first time to something that looked like combat damage when they should have been unable to get into combat.
And don't even get me started on how pointless the numbers are. Both a white deck and a green elf deck would flat-out chuckle upon seeing the opposition being a 67/1 Ork without trample. A 1/1 could kill him, which is absurdly cheap from decks who can generate huge numbers of them from tokens or cheap cards. Also, those numbers are way too huge, even for crazy elf decks or mono-red agro decks. My own mono-green elf deck (which may have resulted in a lot of my high-school classmates hating my guts) would swing with a handful of 20/20 elves (or forests, cause attacking with a bunch of lands is hilarious and somehow practical) at it's most crazy; usually I'd get a win before having anything bigger than an 11/12. I think I once had a 44/45 or something that crazy for a two-headed giant, but that was more for the meme than anything practical.
Overall I really enjoy the concept of this manga, I just find find myself torn by how closely the mechanics mimic MtG, without having combat scenes that make sense from a MtG perspective. I'd give this a pass if the author's point was that this world doesn't perfectly mimic the game rules, but so far that doesn't seem to be a thing.