So, I got Magic: Legends running in Wine (using Heroic game launcher, and decided to write a post about it, in case other people would be interested (tl;dr at the end).

First things first, the game would not launch after installing in Lutris, but I read some people had succcess installing it from the Epic Game Launcher (through Lutris ?). I went with Heroic Game Launcher, the game installation ran without problems.

But, I had black / missing textures, and a lot of frame drops, presumably when new objects / effects were loaded (we are talking about freezes up to several seconds here). I tried with protonGE, but then the game wouldn't launch. Same when activating DXVK on Heroic Game Launcher... and I found out that the DXVK package was simply not installed on my computer !

Switching to DXVK, textures appeared, but there were still freezes. Using Corectrl, I switched the CPU to Performance mode, but the change was not very perceptible.

Then, I remembered reading on protonDB that some games were having trouble when the CPU had a lot of core, using starting at 16, which is the case on my Ryzen 5800x; also, some people had trouble when SMT was enabled on those CPU (including on Windows, especially for Threadrippers) So, I looked on how to disable SMT, and I found that useful script t turn SMT off, which will last until reboot (or if you manually set SMT on).

Magic: Legends was now playing almost perfectly ; switching the CPU to Performance mode helped reducing the last frame drops, and now I can finally enjoy the game


tl;dr:
 
- install the game from Epic Game Launcher / Heroic Game launcher

- make sure DXVK is installed and enabled for the game (if there are black/missing textures, it is probably not enabled)

- if freezes, try disabling SMT / Hyperthreading before launching the game

- set CPU to performance mode to further reduce frame drops

Hope this will be of some use