Let me start by saying I've played a lot of TCGs. I've played Magic, Yu-Gi-Oh, Pokemon, Hearthstone, and furthermore tried a variety of miscellaneous games. I have enough experience in card games to know when I like something.
The plot is predictable enough, but given the type of game, it doesn't bother me much, and it's handled fairly well, if not particularly interesting. It works as a vehicle for the mechanics, and that's okay.
My biggest issue with the tutorial was how much information was being thrown at you at once, and how long it took to actually start playing. The beginning section is divided between trying to absorb how the game works and witnessing bits of story that don't grab you. There wasn't much actual playing, and when I was playing, it felt more like I was picking random cards than actually trying to do any sort of strategic play. It ends up working as neither a tutorial, nor as a game.
Due to the real time strategy element of the battles, it becomes laborious to check what each card does, as it wastes time. You end up having to memorize card art and link it to effects so you know what to play.
After finishing the tutorial, I played for a while on tournament mode, but it always felt like my wins were due to luck rather than actually knowing how the game worked. It didn't seem to matter what cards I used as long as I had picked a powerful avatar and used up my cards fast enough. The way the drawing worked also meant that I could burn a bunch of cards all willy nilly as fast as I could, so I wouldn't have to worry about MP.
I appreciate that the game was made in 2002 and has all these cool mechanics going on, but it does fall flat. It's not very accessible to someone who's playing for the first time.