Didn't see a lot of reviews of people using him as midfielder.
I play him at CM in a 4231 paired with De Jong and he's doing a great job there. I like to have one technical midfielder able to carry the ball forward and keep possession and he's perfect for that.
For me, he's on par with Scream Firmino or even better, which makes him good value considering you can link him with Neymar / Mbappe / Ben Yedder.
For me, he's a key player on my team because he's a complete midfielder. He's always in the right spot and can score with both feet.
Tried different chemistry style like maestro and powerhouse and for me Guardian is the best.
- Nimble dribbling : the ball his glued to his feet,
- Incredible shoot : he score a lot of goals for a CM / CDM with both feet,
- Really good presence on the pitch
- Lack on physical presence in the midfield. I tried him with Kante and It didn't click for me. You might need a Sissoko like player to pair with him